Lakhmir Singh Class 10 Chemistry 4th Chapter Carbon And Its Compounds Solution

Lakhmir Singh Class 10 Chemistry 4th Chapter Carbon And Its Compounds Solution

 

Lakhmir Singh Manjit Kaur Chemistry Solution: Carbon And Its Compounds Chapter 4. Here you get easy Solutions of Lakhmir Singh Class 10 Chemistry Solution Chapter 4. Here we have given Chapter 4 all Solution of Class 10. Its help you to complete your homework.

  • Board – CBSE
  • Text Book – Chemistry
  • Class – 10
  • Chapter – 04

Lakhmir Singh Class 10 Chemistry 4th Chapter Solution

 

 

Very Short Answer Type Questions

 

1) Name the element whose one of the allotropic forms is buckminsterfullerene.

Ans: Carbon is the element whose one of the allotropic form is buckminsterfullerene.

 

2) What are the two properties of carbon which lead to the formation of a large number of carbon compounds ?

Ans: properties of carbon which lead to the formation of a large number of carbon compounds are following :

I) catenation : catenation is the carbon atom to form bond with other atom of carbon atom.

II) Tetravalency : valency of carbon is four and is capable of bonding with four other atom.

 

3) State whether the following statement is true or false : Diamond and graphite are the covalent compounds of carbon elements.

Ans: False.

Diamond and graphite are allotrope of carbon with covalent bonding between different carbon group.

 

4) Name the scientist who disproved the ‘vital force theory’ for the formation of organic compounds.

Ans: Friedrich Wohler is proved the vital force theory for the formation of organic compounds.

 

5) Name the element whose allotropic form is graphite.

Ans: Carbon is the element whose allotropic form is graphite.

 

6) In addition to some propane and ethane, LPG cylinders contain mainly two isomers of another alkane. Name the two isomers and write their condensed structural formulae.

Ans: n butane and iso butane are two isomers of butane found in LPG cylinder.

 

The condensed structural formula of n – butane and Iso – butane are as follows

 

7) Buckminsterfullerene is a spherical molecule in which 60 carbon atoms are arranged in interlocking hexagonal and pentagonal rings of carbon atoms.

 

(a) How many hexagons of carbon atoms are present in one molecule of buckminsterfullerene ?

Ans: 20 hexagons of carbon atoms are present in one molecule of buckminsterfullerene

 

(b) How many pentagons of carbon atoms are present in one molecule of buckminsterfullerene ?

Ans: 12 pentagons of carbon atoms are present in one molecule of buckminsterfullerene

 

8) Name the black substance of pencil. Will the current flow through the electrical circuit when we use the sharpened ends of the pencil to complete the circuit ?

Ans: black substance in pencil is graphite. Yes, current flow through the electrical circuit when we use the sharpened ends of the pencil to complete the circuit because graphite is good conductor of electricity.

 

9) How does graphite act as a lubricant ?

Ans: Graphite act as lubricant because graphite has hexagonal structure and in which weak van der waals force in layer of the carbon atom crystal. Due to weak van der waals force, the layers of carbon atom in graphite can slide over one another hence its Slippery in nature and capable of acting as a lubricant.

 

10) Name the hardest natural substance known.

Ans: Diamond is the hardest natural substance known .

 

11) Which of the following molecule is called buckminsterfullerene ? C90 C60 C70 C120

Ans: C60 molecule is called buckminsterfullerene .

 

12) Give the name and structural formula of an alkyl group.

Ans: the name and structural formula of an alkyl group.

 

13) Write the electron-dot structures for : (i) ethane, (ii) ethene, and (iii) ethyne.

Ans: the electron-dot structures for : (i) ethane, (ii) ethene, and (iii) ethyne are the following :

 

14) Give the IUPAC name of the following compound : C2H6

Ans: The IUPAC name of the C2H6 is Ethane.

 

15) Write the structural formula of propene.

Ans : structural formula of propene C3H6 is

 

16) Write the structural formula of propyne.

Ans: the structural formula of propyne ( C3H4) is following :

 

17) Write the structural formula of butane.

Ans: structural formula of propene C4H10 is

 

18) What do you call the compounds having the same molecular formula but different structural arrangements of atoms ?

Ans: the compounds having the same molecular formula but different structural arrangements of atoms is called isomers.

 

19) Write the names of any two isomers represented by the molecular formula C5H12.

Ans: The molecular formula of pentane (C5H12) is the Isopentane and neopentane.

 

20. Write down (i) structural formula, and (ii) electron-dot formula, of any one isomer of hexane (C6H14), other than n-hexane.

 

21) Fill in the following blanks with suitable words :

(a) Ans: The form of carbon which is known as black lead is graphite .

(b) Ans: The form of carbon which is used as a lubricant at high temperature is graphite

(c) Ans: Compounds of carbon with hydrogen alone are called hydrocarbon.

(d) Ans: CnH2n is the general formula of alkene hydrocarbons.

(e) Ans: Hydrocarbons having the general formula CnH2n–2 are called ethene

(f) Ans: Ethene and ethyne are examples of unsaturated hydrocarbons.

(g) Ans: Ethyne has two carbon-hydrogen single bonds.

(h) Ans: Carbon compounds have usually low melting points and boiling points because they are covalent in nature.

(i) Ans: The property of carbon atoms to form long chain in compound is called catenation

(j) Ans: The general formula CnH2n for cycloalkanes is the same as that of alkanes.

(k) Ans: The IUPAC name of ethylene is ethene.

(l) Ans: The IUPAC name of acetylene is ethyne

Short Answer Type Questions:

22)

(a) What is the atomic number of carbon. Write its electronic configuration.

Ans: The atomic number of carbon is 6.

The electronic configuration of carbon is – 1S2 2S2 2P2or 2,4

 

(b) What type of chemical bonds are formed by carbon ? Why ?

Ans: Covalent type of chemical bonds are formed by carbon. Carbon valancy is 4 due to this carbon not lose or gain electron to other atom. It share electron and form covalent bond.

 

(c) Name the three allotropic forms of carbon.

Ans: Diamond, graphite, Fullerene are three allotropic form of carbon.

 

23)

(a) What is the general name of all the compounds made up of carbon and hydrogen ?

Ans: Hydrocarbon is the general name of all the compound made up of carbon and hydrogen.

 

(b) Why does carbon form compounds mainly by covalent bonding ?

Ans: Carbon is tetravalent compound and valency of carbon is 4 therefore carbon not gain Or loss of of electron. Carbon share electron and form bond.

 

24)

(a) What is meant by catenation ? Name two elements which exhibit the property of catenation.

Ans: Catenation is the property of self combination of carbon atom to form a long chain. Carbon and silicon elements exhibit the property of catenation.

 

(b) Write the names and structural formulae of all the possible isomers of hexane.

Ans:

 

25)

(a) What is buckminsterfullerene ? How is it related to diamond and graphite ?

Ans : buckminsterfullerene is the allotrope of carbon containing cluster of 60 carbon atom that are arranged in the regular pentagonal and hexagonal to form hollow cage. The named of this type of allotrope of carbon was named recognised late Buckminster Fuller geodesic dome these structure like buckyball. The properties of  buckminsterfullerene is different than  diamond and graphite, such as superconductivity and ability of to trap other chemicals.

(b) Why is diamond used for making cutting tools (like glass cutters) but graphite is not ?

Ans: Diamond is very hard compound and graphite is soft hence diamond used for making cutting tools (like glass cutters) but graphite is not.

 

(c) Why is graphite used for making dry cell electrodes but diamond is not ?

Ans: graphite is good conductor of electricity but diamond is bad conductor of electricity hence  graphite used for making dry cell electrodes but diamond is not.

 

26.

(a) Give the general formula of an : (i) alkane (ii) alkene (iii) alkyne.

Ans: (i) alkane ­– CnH2n+2

(ii) alkene – CnH2n

(iii) alkyne – CnHn-2

 

b) Classify the following compounds as alkanes, alkenes and alkynes : C2H4, C3H4, C4H8, C5H12, C5H8, C3H8, C6H6

Ans:

Alkanes : C5H12 , C3H8

Alkenes : C2H4 , C4H8

Alkynes:  C3H4,  C5H8

 

27)

(a) Friedrich Wohler converted an inorganic compound into an organic compound in the laboratory.

(i) Give the name and formula of inorganic compound.

Ans: name of inorganic compound is ammonium cyanate and formula is NH4NCO.

 

(ii) Write the name and formula of organic compound formed

Ans: the name of organic compound formed is Urea and formula is CO(NH2) 2

(b) Give the molecular formula of butane and mention the names of its two isomers. Name one fuel which contains both these isomers.

Ans:  the molecular formula of butane  is C4H10

the names of two isomers of butane are n-butane and iso- butane .

 

28)

(a) Give IUPAC names and formulae of an organic compound containing single bonds and the other containing a triple bond.

Ans:  The organic compounds containing single bonds that is Methane.

The organic compounds containing triple bond that is ethyne.

 

(b) Which of the following is the molecular formula of benzene ? C6H6, C6H10, C6H12, C6H14

Ans:  molecular formula of benzene is C6H6.

 

(c) Which of the two has a branched chain : isobutane or normal butane ?

Ans: Isobutane has branched chain and while normal butane has single chain of carbon atoms.

 

29) Catenation is the ability of an atom to form bonds with other atoms of the same element. It is exhibited by both carbon and silicon. Compare the ability of catenation of the two elements. Give reasons.

Ans: Carbon and silicon have the catenation property. Due to this catenation property both silicon and carbon atoms ability to form bond with other atoms of the same elements. The compounds which are made by silicon are less reactive and less stable but those compound are made by carbon atom are more reactive and more stable and carbon will show more catenation property as compare to silicon because carbon size of carbon is smaller than silicon ,carbon atom form bond but in which atoms are strongly held with each other as compare to silicon.

30) (a) How can diamonds be made artificially ? How do synthetic diamonds differ from natural ones ?

Ans: Diamond can be made by artificially by treat with pure carbon to very high pressure and temperature. Synthetic diamonds are size is small and pure diamond size is large .

 

(b) Give any two differences between the properties of diamond and graphite. What causes these differences ?

Ans: two differences between the properties of diamond and graphite are :

  • Diamond is hard but graphite is soft.
  • Diamond is bad conductor of electricity whereas graphite is good conductor of electricity.

The diamond and graphite physical properties are different because of the different arrangement of carbon atoms and bonding in them.

 

31) 

(a) Why does the element carbon from a large number of carbon compounds ?

Ans: carbon from a large number of carbon compounds because carbon atoms can link with one another by means of covalent bond to form long chain.

 

(b) Write down the structures and names of two isomers of butane (C4H10)

Ans: two isomers of butane (C4H10) are n butane and iso-butane.

 

32) 

(a) Give the name and structural formula of one member each of the following : (i) alkane (ii) alkene (iii) alkyne (iv) cycloalkane

 

(b) Give the common name of

(i) ethyne

Ans: common name of ethyne is acetylene.

(ii) ethene.

Ans: common name of ethene is Ethylene.

(c) Write the molecular formula and structure of benzene.

 

33)

 

(a) What is the unique property of carbon atom ? How is this property helpful to us ?

Ans: The most unique property of carbon atom is Catenation. Carbon atom combine itself, atom to atom form long chain Or form carbon compound .

(b) Explain why, diamond is hard while graphite is soft (though both are made of carbon atoms).

Ans: Diamond is hard because in diamond carbon atom form strong four covalent bond in tetrahedral structure but graphite is soft because In graphite carbon atom form bond in layers and in which weak Vander wall force present due to this graphite is soft and slippery.

4.

(a) Giving their structures, state the number of single bonds, double bonds and triple bonds (if any) in the following compounds : (i) ethyne (ii) ethene (iii) benzene

Ans:

(b) Write the molecular formula and structure of cyclohexane. How many covalent bonds are there in a molecule of cyclohexane

 

35)

(a) Write two points of difference in the structures of diamond and graphite.

Diamond

  • Each carbon atom are combined to four carbon atom.
  • The tetrahedral arrangement of carbon atom in in diamond.

Graphite

  •  Each carbon atom are combined to four carbon atom.
  •  The flat hexagonal ring like structure of graphite.

 

(b) Explain why, graphite can be used as a lubricant but diamond cannot.

Ans: Graphite can be used as lubricant because graphite is soft and slippery but diamond is hard hence not use as lubricant.

 

(c) Explain why, diamond can be used in rock drilling equipment but graphite cannot.

Ans: Diamond is use in rock drilling equipment because diamond is very hard and it contain rigid structure but graphite is soft hence not use in rock drilling equipment.

 

(d) State one use of diamond which depends on its ‘extraordinary brilliance’ and one use of graphite which depends on its being ‘black and quite soft’.

Ans:

one use of Diamond :- Diamond is use for making jewellery.

One use of graphite:-Graphite is use for making pencil leads.

 

Long Answer Type Questions

 

36)

(a) What is diamond ? Of what substance is diamond made ?
Ans: Diamond has tetrahedron structure and hard, colorless transparent. Diamond is made up of carbon

 

(b) Describe the structure of diamond. Draw a simple diagram to show the arrangement of carbon atoms in diamond.

Ans: Diamond is made up of carbon. In diamond molecule each carbon atom linked to four other carbon by strong covalent bond forming tetrahedron structure. Diamond is also hard and form rigid structure.
Simple diagram of arrangement of carbon atom in diamond is following :

 

(c) Explain why, diamond has a high melting point.

Ans: Diamond is very hard molecule and in which strong covalent bond between carbon atom due to this these covalent bond not easily break. It required more heat to break bond hence diamond has more melting point.

 

(d) State any two uses of diamond.

Ans: The two uses of diamond are following:

  • Diamond is use for making jewellery.
  • Diamond is use in rock drilling equipment

37)

(a) What is graphite ? Of what substance is graphite made ?

Ans: Graphite is a greyish-black opaque substance. It is made up of carbon.

(b) Describe the structure of graphite with the help of a labelled diagram.

Ans: 

(c) Why is graphite a good conductor of electricity but diamond is a non-conductor of electricity ?

Ans: Graphite is good conductor of electricity because graphite contain free electrons but in absence of free electrons diamond is a non conductor of electricity.

 

(d) State any two uses of graphite.

Ans: The two uses of graphite are following:

  • graphite use as lubricant.
  • graphite use for making pencil lead.

 

38)

 

 (a) Explain the term ‘isomers’. Give one example of isomers.

Ans. Compound contain same molecular formula but different structural formula is called isomers.

 

(b) Write (i) structural formula, and (ii) electron-dot structure, of any one isomer of n-heptane (C7H16) .

Ans: 

 

(c) Write IUPAC name of the compound having the formula n-C4H10.

Ans: IUPAC name of the compound having the formula n-C4H10 is butane.

 

(d) Give the IUPAC names for the following :

 

39) 

(a) What are hydrocarbons ? Explain with examples.

Ans: Compound is made up of hydrogen and carbon is called hydrocarbon. For example methane (CH4), ethane(C2H6), ethene (C2H4) , ethyne (C2H2)  all are hydrocarbon.

 

(b) Explain the meaning of saturated and unsaturated hydrocarbons with two examples each.

Ans: Saturated hydrocarbon:

Saturated hydrocarbon is carbon atoms linked by single bond. For example – methane(CH4)

Unsaturated hydrocarbon:

Unsaturated hydrocarbon is two carbon atoms are linked by double or triple bond. For example-Benzene (C6H6).

 

(c) Give the names and structural formulae of one saturated cyclic hydrocarbon and one unsaturated cyclic hydrocarbon.

Ans: Cyclic saturated hydrocarbon is Cyclohexane (C6H6).

 

Unsaturated cyclic hydrocarbon is benzene (C6H6) :

 

(d) Give one example of a hydrocarbon, other than pentane, having more than three isomers.

Ans: Hexane has more than three isomers.

 

(e) How many isomers of the following hydrocarbons are possible ?

(i) C3H8 – No isomer present.

(ii) C4H10 – Two isomers present.

(iii) C5H12 –Three isomers present.

(iv) C6H14 – Five isomers present.

 

Part – B

 

Very Short Answer Type Questions –

1 .write the molecular formula of ethanol.

Ans: Molecular formula of ethanol is C2H5OH.

2. What is the next higher homologue of methanol (CH3OH).

Ans: The next higher homologue of methanol (CH3OH) is ethanol C2H5OH.

3. Identify the functional group present in the following compound and name it according to IUPAC system : CH3OH

Ans: In CH3OH molecule -OH (alcohol) functional group present.

IUPAC Name of molecule CH3OH is Methanol.

4. aldehyde Give the common name and IUPAC name of the simplest.

Ans: The common name of aldehyde is formaldehyde.

IUPAC name of formaldehyde is methanol.

 

5.What is the common name of methanol ?

Ans: the common name of methanol is methyl alcohol.

6. Write the names of the following functional groups :

Ans:

 

7) Name the simplest ketone.

Ans: The simplest ketone is acetone.

And its structural formula is following:

 

8) What is the common name of propanone ?

Ans: The common name of propanone (CH3COCCH3) is acetone.

 

9) Write the IUPAC names of the following :

(i) CH3COCH3 (ii) CH3COCH2CH3

Ans:

  • The IUPAC name of CH3COCH3 is acetone because in which 2 methyl and 1carbonyl group present.
  • The IUPAC name of CH3COCH2CH3 is butanone because in which 2 methyl 1 methylene and 1 carbonyl group present.

 

10) Write the name and chemical formula of the simplest organic acid.

Ans: The simplest organic acid is formic acid and its chemical formula is (HCOOH).

 

11) Write the IUPAC names, common names and formulae of the first two members of the homologous series of carboxylic acids.

Ans: Methanolic acid and Ethanoic Acid are the first two members of the homologous series of carboxylic acids.

 

12) What is the common name of : (a) Methanoic acid, and (b) ethanoic acid ?

Ans: Common name of Methanoic acid isformic acid.

The common name of Ethanoic acid is acetic acid.

 

13) Draw the structures for the following compounds : (a) Ethanoic acid (b) Propionic acid

Ans:  Ethanoic acid and Propionic acid structures are the following:

 

14) Give the common names and IUPAC names of the following compounds : (a) HCOOH (b) CH3COOH

Ans:

        Compounds

Common name

IUPAC name

          HCOOH

Formic acid Methanolic acid
         CH3COOH Acetic acid

Ethanoic acid


 

15) Give the name and structural formula of one homologue of HCOOH.


Ans: Ethanoic acid (CH3COOH)  is the next homologue of HCOOH.

 

16) Write the formulae of : (a) methanoic acid, and (b) ethanoic acid.

Ans: The formula of Methanoic acid is HCOOH)
The formula of Ethanoic acid is CH3COOH)

 

17) Give the common name and IUPAC name of C2H5OH)
Ans: Common name of C2H5OH is ethyl alcohol
IUPAC name of C2H5OH is ethanol)

 

18) Give the IUPAC name of the following compound : C3H7OH

Ans: The IUPAC name of C3H7OH compound is Propanol)

 

19) Give the name and structural formula of one member of the following : Alcohols

Ans: The member of alcohol is ethanol (C2H5OH))

 

20) Give IUPAC names of the following compounds :
(a) C4H9OH

Ans: The IUPAC name of C4H9OH compound is butanol)

(b) C5H11OH

Ans: The IUPAC name of C5H11OH compound is pentanol)

21) What is the common name of methanol ?

Ans: The common name of methanol is methyl alcohol)

 

22) What is the difference between two consecutive homologues :

(i) in terms of molecular mass ?

Ans:14u is the difference between two consecutive homologous in terms of molecular mass)

(ii) in terms of number and kind of atoms per molecule ?

Ans: The difference between two consecutive homologous in term of number and kind of atoms per molecule is 1 carbon atom and 2 hydrogen atom in their molecular formula)

 

23) What type of fuels :

(a) burn with a flame ?

Ans: Those fuels can be converted into vapour form which are burn with a flame)

(b) burn without a flame ?

Ans: Those fuels can not be converted into vapour form which are burn without a flame)

24) State whether the following statement is true or false :

The minimum number of carbon atoms in a ketone molecule is two)
Ans: The above statement is False)
The minimum number of carbon atom in ketone molecule is not less than three carbon atom) Propanone Or acetone is (CH3COCH3) is first member of ketone family)

 

25) Fill in the following blanks with suitable words –

(a) Ans: The next higher homologue of ethanol is propanol.

(b) Ans: The next homologue of C2H5OH is C3H7OH

(c) Ans: The next higher homologue of ethane is propane.

(d)  Ans: The functional group present in ethanol is -OH (alcohol) .

(e) Ans: Organic compounds having functional group are known as carboxylic acid.

 

Short Answer Type Questions

 

26)

(a) Give the general name of the class of compounds having the general formula CnH2n 2 ) Write name of the first member of this homologous series)

Ans: the general name of the class of compounds having the general formula CnH2n – 2 is Alkynes. The name of the first member of this homologous series is ethyne)

 

(b) The general formula of a homologous series of carbon compounds is CnH2n) Write the molecular formulae of the second and fourth members of the series)

Ans: The general formula of a homologous series of carbon compounds is CnH2n is alkenes)

The molecular formulae of the second and fourth members of the series are C3H6 and C4H8)

 

(c) Write the molecular formulae of the third and fifth members of homologous series of carbon compounds represented by the general formula CnH2n+2.

Ans: The general formulae of the third and fifth members of homologous series CnH2n+2 will have the molecular formula C3H8 and C5H12)

27
(a) Give the names and structural formulae of the next two higher homologues of methane)

Ans: The next two higher homologues of methane are ethane and propane.
The structural formulae of the next two higher homologues of methane are the following :

 

(b) The molecular formula of a hydrocarbon is C10H18. Name its homologous series.

Ans: The molecular formula of a hydrocarbon is C10H18 and its homologous series is Alkynes (CnH2n-2).

 

(c) Select the hydrocarbons which are members of the same homologous series. Give the name of each series. C5H10 ; C3H8 ;C6H10 ;C4H10; C7H12 ;C8H16

Ans: Alkanes : C3H8, C4H10.
Alkenes : C5H10, C8H16
Alkynes : C6H10, C7H12

28.

(a) Give the molecular formula of one homologue of each of the following : (i) C3H6 (ii) C2H6 (iii) C2H2

Ans: The molecular formula of one homologue of each of the following are
1. C3H6 – C4H8
2. C2H6 – C2H6
3. C2H2 – C3H4

 

(b) What is the difference in the molecular mass of any two adjacent homologues ?

Ans: The difference in the molecular mass of the any two adjacent homologue is 14u (-CH2).

 

(c) By how many carbon atoms and hydrogen atoms do any two adjacent homologues differ ?
Ans: One carbon atom and two hydrogen atom that is by a -CH2 group.

 

29.

(a) Write the formula of the functional group present in carboxylic acids.
Ans: -COOH is the functional group present in carboxylic acid.

 

(b) Name the functional group present in CH3 C CH.
Ans: the functional group present in CH3CCH is alkyne

 

(c) Name the functional groups present in the following compounds :
(i) CH3CHO

Ans: In above compound Aldehyde functional group present.

 

(ii) CH3CH2COOH
Ans: In above compound carboxylic acid functional group present.

 

(iii) CH3COCH3
Ans: In above compound ketone functional group present.

 

(iv) CH3CH2CH2OH
Ans: In above compound alcohol functional group present.

 

30.

(a) Write the IUPAC name and common name of CH3Cl.

Ans: IUPAC name of CH3Cl is chloromethane
common name of CH3Cl is methyl chloride.

 

(b) Draw the structure of chlorobutane.

Ans:

 

(c) Draw the structure for bromopentane. Are structural isomers possible for bromopentane ?

 

 

31 (a) Write the name and formula of an organic compound containing a ketone functional group.

Ans: The name of an organic compound containing a ketone functional group is acetone.

The formula of an organic compound containing a ketone functional group is acetone that is CH3COCH3

 

(b) Write the names and formulae for the first three members of the homologous series of chloroalkanes.

Ans: The first three members of the homologous series of chloroalkanes are :

  • Chloromethane – CH3Cl
  • Chloroethane – C2H5Cl
  • Chloropropane -C3H7Cl

 

(c) How would you name the following compound ? CH3—CH2—Br

Ans: The name of the compound CH3-CH2-Br is ethyl bromide.

 

32) 

(a) What is the general name of the organic compounds containing -CO- the group ?

Ans: ketone is the organic compound containing -CO- group.

 

(b) Which of the following compounds contains a carboxylic acid group ? CH3OH, CH3COOH, CH3CHO, CH3COCH3

Ans: The carboxylic acid group that is -COOH group this group contain CH3COOH compound

 

(c) How would you name the following compound ?

Ans: The name of above compound is methanal.

 

33.

(a) Define a homologous series. Give the name and structural formula of one homologue of the following : CH3OH

Ans:  Definition – Homologous series is series of related  chemical compound that have same structural formula but different structural formula of by a fixed group of atoms.

CH3OH is methanol compound. The homologue of CH3OH is ethanol (C2H5OH) and its structural formula is following:

 

(b) Write the molecular formula of the third member of the homologous series of carbon compounds with general formula CnH2n+ 1OH.

Ans: The third member of homologous series of carbon compound is propanol and its general formula CnH2n+ 1OH but molecular formula is C3H7OH.

 

(c) Name any two fossil fuels.

Ans: Coal and biomass are fossil fuels.

 

34.

(a) Draw the structures for the following compounds : (a) Propanone (b) Butanone

Ans:  The structures of Propanone and Butanone are following :

 

(b) Write the IUPAC names of the following :

(i) HCHO

Ans: The IUPAC name of the HCHO is Methanol.

 

(ii) CH3CHO

Ans: The IUPAC name of the CH3CHO is Ethanol.

 

(iii) CH3CH2CHO

Ans: The IUPAC name of the CH3CH2CHO is Propanol.

 

(iv) CH3CH2CH2CHO

Ans: The IUPAC name of the CH3CH2CH2CHO is Butanol.

 

(c) Which functional group is likely to be present in an organic compound having the molecular formula C4H10O ? Write the formula of the organic compound.

Ans: Alcohol(-OH)functional group is likely to be present in an organic compound having the molecular formulaC4H10O.

The formula of the compound is C4H9OH

 

35.

(a) Match the formulae in group A with appropriate names from group B :

Group A Group B
CH3COOH Ethanol
CH3CHO Methanol
CH3OH Ethanoic acid

Ans:

CH3COOH – Ethanoic acid

CH3CHO – Ethanol

CH3OH– Methanoic acid

 

(b) Draw the structure of butanoic acid.

Ans:

(c) What is the IUPAC name of acetic acid ?

Ans: The IUPAC name of ascetic acid is the ethanoic acid.

 

36)

(a) Which functional group do you think can be present in an organic compound having the molecular formula C5H10O2 ? Write the formula of the organic compound.

Ans: Carboxylic acid (-COOH) functional group can be present in an organic compound having the molecular formula C5H10O2

the formula of the organic compound is the C4H9COOH.

 

(b) Give one example each of the compounds having the following functional groups : (i) Aldehyde group (ii) Alcohol group (iii) Carboxylic acid group (iv) Halo group

Ans: example each of the compounds having the following functional groups :

 

(c) Give one example each of the compounds having the following functional groups : (i) Alkene group (ii) Alkyne group

Ans:

 

37) (a) What is the molecular formula and structure of the alcohol which can be thought to be derived from pentane ?

AnS: C5H11OH is molecular formula of the alcohol which can be thought to be derived from pentane.

The structural formula of pentanol is following:

(b) Write the names of the following functional groups :

(i) —CHO

Ans:  The above functional group name is Aldehyde

(ii) —OH

Ans:   The above functional group name is Alcohol

(iii) —COOH

Ans: The above functional group name is Carboxylic acid

(iv)

Ans: The above functional group name is carboxylic acid.

(v) —X

Ans: The above functional group name is  Halogen

(c) What makes the candle flame yellow and luminous ?

Ans: The candle flame yellow and luminous because when candle is burn, incomplete combustion of the of wax in air. The candle wax does not get proper oxygen in air therefore not burn completely and some carbon particles remain as it is, when at the high flame this particles burn then candle flame yellow and luminous.

 

Long Answer Type Questions

 

 38) (a) What is a homologous series ? Explain with an example.

Ans: Homologous series is series of related  chemical compound that have same structural formula but different structural formula of by a fixed group of atoms.

CH3OH is methanol compound. The homologue of CH3OH is ethanol (C2H5OH) .

 

(b) State two characteristics of a homologous series.

Ans: The two characteristics of a homologous series:

  • Homologous series contain same molecular formula.
  • The chemical property are same not change gradually.

 

(c) The molecular formula of an organic compound is C18H36. Name its homologous series.

Ans: The molecular formula of an organic compound is C18H36 it’s homologous series is alkenes CnH2n,

 

(d) Select the hydrocarbons which belong to the same homologous series. Give the name of each series. CH4, C2H2, C2H4, C2H6, C4H10, C3H4, C3H6 .

Ans: Alkanes : CH4, C2H6, C4H10

Alkenes : C2H4, C3H6

Alkynes : C2H2, C3H4

(e) What is meant by ‘heteroatom’? Give examples. Write the names and formulae of two organic compounds containing different heteroatoms.

Ans: Heteroatoms are those atom which contain an atom other than carbon such as nitrogen, sulphur, phosphorus.

For example – Nitrogen, Sulphur, Oxygen.

the names and formulae of two organic compounds containing different heteroatoms

  • Chloromethane – CH3Cl
  • Formaldehyde – HCHO

 

39) 

(a) What is meant by a functional group ? Explain with an example.

Ans: A functional group is defined as an atoms or a groups of atoms that are effectively determine the chemical properties of an organic compounds.

For example – CH3OH methanol in which OH means alcoholic functional group present.

(b) Write three common functional groups present in organic compounds. Give their symbols/formulae.

Ans: three common functional groups present in organic compounds and their symbols/formulae following:

Organic compounds Functional group    General formula
Haloalkanes            -X(Halide group)                    R-X
Alcohol -OH(hydroxyl group)                   R-OH
Ketone -CO- (keto)                 R-CO-R’

 

(c) Name the functional groups present in the following compounds :

(i) CH3COOH

Ans: Carboxylic acid

(ii) CH3CH2CHO

Ans: Aldehyde group

(iii) C2H5OH

Ans: Alcohol group

(iv) CH3COCH2CH3

Ans: ketone group

 

(d) Name the functional group which always occurs in the middle of a carbon chain.

Ans: -CO-functional group which always occurs in the middle of a carbon chain.

(e) Draw the structures for the following compounds : (i) Ethanal (ii) Propanal (iii) Butanal (iv) Pentanal

Ans:

40.

(a) What happens when carbon burns in air ? Write the chemical equation of the reaction which takes place.

Ans: C + O2 → CO2 + heat + light

when Carbon burn in presence of oxygen in air to form by carbon dioxide some amount of heat is release.

 

(b) Why are coal and petroleum called fossil fuels ?

Ans: For the long period prehistoric plants and animals under the earth and they are decompose and form by fossil fuels that is coal and petroleum.

 

(c) Explain how coal was formed in the earth.

Ans: Coal was formed in the earth , million of the year ago due  to earthquake, volcanoes, forest fire the plant and animals decompose under the surface of earth. Due to this prehistoric plants and animals decompose form and coal was found.

 

(d) Describe how petroleum was formed in the earth.

Ans: million years ago aquatic plant , animal, algae, bacteria live in sea. Prehistoric plants, microorganism, animal they buried and decompose under the deeply sea level for this way petroleum was form in the earth.

 

(e) Name a fossil fuel other than coal and petroleum.

Ans: Natural gas is a fossil fuel other than coal and petroleum.

Part – C

Very Short Answer Type Questions

 

1) Name the gas evolved when ethanoic acid is added to sodium carbonate. How would you prove the presence of this gas ?

Ans: When ethanoic acid is added to sodium carbonate the carbon dioxide gas evolved.

2CH3COOH + Na2CO3 →2CH3COONa + CO2 + H2O

When lime water pass through carbon dioxide gas milky ppt form. in this way we prove the presence of carbon dioxide gas .

Ca(OH)2 + CO2 → CaCO3 + H2O

                                           Lime water             milky ppt

 

2) Which of the following will give brisk effervescence with sodium hydrogen carbonate and why ? CH3COOH, CH3CH2OH

Ans: CH3COOH + NaHCO3 → CH3COONa + CO2 + H2O

CH3COOH it is ethanoic acid. When ethanoic acid react with sodium hydrogen carbonate to form sodium ethanoate, carbon dioxide and water. Due to carbon dioxide gas evolved it give the brisk effervescences.

 

3) Name the functional group present in an organic compound which gives brisk effervescence with NaHCO3.

Ans: Carboxylic acid (-COOH) functional group present in an organic compound which gives brisk effervescence with NaHCO3.

 

CH3COOH + NaHCO3 → CH3COONa + CO2 + H2O

Carboxylic acid + sodium bicarbonate → sodium ethanoate carbon dioxide water

 

In this reaction CO2 gas evolved it give brisk effervescence .

 

4) Name the hydrocarbon formed when ethanol is heated with conc. H2SO4 at 170°C ? What is this reaction known as ?

Ans:

when ethanol is heated with conc. H2SO4 at 170°C the ethene hydrocarbon is formed. This type of reaction is known as dehydration.

 

5) Why does ethyne (acetylene) burn with a sooty flame ?

Ans: ethyne (acetylene) burn with a sooty flame because ethyne is unsaturated hydrocarbon and ethyne contain more percentage of carbon . Due to this in presence of oxygen in air ethyne not oxide easily in air.

 

6) Name the product formed when hydrogen is added to ethene.

Ans:

When hydrogen is added to ethene in presence of Nickel metal to formed ethane as a product this is hydrogenation reaction.

 

7) Explain why, ethene decolourises bromine water whereas ethane does not.

Ans: Ethene decolourises bromine water because ethene is unsaturated compound and when react with bromine water ethene colour appear as reddish brown but ethane does not appear decolourises because ethane is saturated compound and it react with bromine water no color change.

 

8) Name two catalysts which can be used in the hydrogenation of unsaturated compounds.
Ans: In the hydrogenation of unsaturated compounds nickel and palladium this two metals are used.

 

9) State two disadvantages of incomplete combustion.

Ans: The two disadvantaged of incomplete combustion are the following:

1) Due to incomplete combustion fuel oxidised partial and low energy produce.

2) In incomplete combustion carbon monoxide gas produces and it is Poisonous.

 

10) What happens when (give chemical equation) : Sodium reacts with ethanol (ethyl alcohol)

Ans:- 2C2H5OH + 2Na → 2C2H5O- Na+  + H2

When ethyl alcohol react with sodium to form sodium ethoxide and hydrogen gas effervescence act as.

 

11) Describe one reaction of ethanol.

Ans: 2C2H5OH + 2Na → 2C2H5O- Na+  + H2

When ethanol react with sodium metal to form sodium ethoxide and rapid effervescence of hydrogen gas generate.

 

12) Name one liquid carbon compound which is being used as an additive in petrol in some countries.

Ans: Ethanol liquid carbon compound which is being used as an additive in petrol in some countries.

 

13) What are the raw materials required for making soap in a laboratory (or at home) ?

Ans: The raw materials required for making soap in a laboratory are the following:

  • Common salt means sodium Chloride
  • Sodium hydroxide it is caustic soda
  • Castor oil

 

14) Would you be able to check whether water is hard by using a detergent ? Why ?

Ans: No we are not able to check whether water is hard by using a detergent because in soft water detergent forms lather but calcium and magnesium are present in water and detergent not react with them hence not possible to check water is hard by using detergent.

 

15) Describe a test for carboxylic acids.

Ans: CH3COOH + NaHCO3 → CH3COONa + CO2 + H2O

CH3COOH it is ethanoic acid. When ethanoic acid react with sodium hydrogen carbonate to form sodium ethanoate, carbon dioxide and water. Due to carbon dioxide gas evolved it give the brisk effervescences this reaction proceeds in presence of carboxylic acid.

 

16.Why is the conversion of ethanol into ethanoic acid an oxidation reaction ?

Ans:

When ethanol in presence of oxygen to produce Ethanoic acid. This is the oxidation reaction bin when oxygen added then ethanol convert into Ethanoic acid.

 

17) explain why, alkanes are excellent fuels.

Ans: Alkanes are excellent fuels because alkanes are saturated hydrocarbon

 

18) Name one chemical compound which can be used to distinguish between ethanol and ethanoic acid.

Ans: Sodium hydrogen carbonate compound which can be used to distinguish between ethanol and ethanoic acid.

CH3COOH + NaHCO3 → CH3COONa + CO2 + H2O

 

 

19) Complete the following equations :

Ans:

 

 

20) Complete and balance the following equations :

 

Ans:

 

21. Fill in the following blanks with suitable words :

 

(a) Ans: The process of burning of a hydrocarbon in the presence of air to give CO2, H2O, heat and light is known as combustion

 

(b) Ans: The sodium salt of a long chain fatty acid is called soap

 

(c) Ans: Detergent is better than soap for washing clothes when the water is hard.

 

(d) Ans: The organic acid present in vinegar is ethanoic acid.

 

Short Answer Type Questions :

22. Which of the following hydrocarbons will give substitution reactions and why ? CH4, C3H6, C3H8, C4H6, C5H12, C5H10

Ans: CH4, C3H8, C5H12 hydrocarbons will give substitution reactions because CH4, C3H8, C5H12 hydrocarbons are saturated hydrocarbon.

 

23. Which of the following will give addition reactions and why ? C4H10, C2H6, C2H4, CH4, C3H8, C3H4

Ans: C2H4, C3H4 compounds will give addition reactions because these compounds are unsaturated hydrocarbon.

 

24.

(a) Write the chemical equation of the reaction which takes place during the burning of ethanol in air.

The above reaction which take place during the burning of ethanol with oxygen in air the carbon dioxide gas evolved and form by water and light, heat.

 

(b) Why is ethanol used as a fuel ?

Ans: Ethanol used as a fuel because ethanol is easily and mote explosive liquid when ethanol burn in presence of oxygen in air it give heat and light.

 

(c) State two uses of ethanol (other than as a fuel).

Ans: The two uses of ethanol as following:

  • Ethanol is used in alcoholic beverages.
  • Ethanol is used in medicine and drugs.

 

25) 

(a) What happens when propanoic acid is warmed with methanol in the presence of a few drops of concentrated sulphuric acid ? Write equation of the reaction involved.

Ans-

when propanoic acid is warmed with methanol in the presence of a few drops of concentrated sulphuric acid to form by methyl Propanoate ester and water form.

 

(b) What change will you observe if you test soap solution with a litmus paper (red and blue) ? Give reason for your observation.

Ans: Soap contain salt and acid in which sodium hydroxide is act as strong base and carboxylic acid is weak acid. when soap dissolve in water, the solution turn basic solution hence red litmus turns to blue.

 

(c) What is meant by denatured alcohol ? What is the need to denature alcohol ?

Ans: Denatured alcohol is the ethyl alcohol. Denatured alcohol is made by drinking purpose in which least amount of substance like copper, methanol pyridine.
Denature alcohol is need to misuse of prevent of industrial alcohol for drinking purpose or misuse in marketing.

 

26.
(a) How would you test for an alcohol ?

Ans: Test for an alcohol : take dry test tube take few drops of alcohol add small piece of sodium metal when the bubbles of hydrogen gas are produced then alcohol is present.

 

(b) Give the harmful effects of drinking alcohol.

Ans: The harmful effects of drinking alcohol :

  • Due to drinking alcohol long time the mental health problems, including depression and anxiety.
  • High blood pressure, heart disease, liver problems and digestive problems for drinking alcohol.

 

(c) Explain why, methanol is much more dangerous to drink than ethanol.

Ans: Methanol is dangerous to drink ethanol because methanol highly toxic. When methanol to use drinking purpose optical nerve damage and permanent blindness in person.

 

27) How would you convert :

(a) ethanol into ethene ?

Ans:

When ethanol convert into ethene by using few drops of concentrated sulphuric acid at 170°C and

this process is known as dehydration.

 

(b) propanol into propanoic acid ? Name the process in each case and write the equations of the reactions involved.

Ans: Propanol convert into propanoic acid in presence of oxygen and alkaline potassium permanganate

 

28. Give reasons for the following observations

(a) Air holes of a gas burner have to be adjusted when the vessels being heated get blackened by the flame.

Ans: Air holes of a gas burner have to be adjusted when the vessels being heated get blackened by the flame because the vessels are blackened due to this gas stove air holes block and least amount of oxygen supply to hence fuels not burning completely.

 

(b) Use of synthetic detergents causes pollution of water.

Ans: Synthetic detergent like some soaps are not easily biodegradable they are not decomposes with microorganisms like bacteria and hence these are causes of water pollution.

 

29.

(a) What would be observed on adding a 5% alkaline potassium permanganate solution drop by drop to some warm ethanol in a test-tube ? Write the name of the compound formed during the chemical reaction. Also write chemical equation of the reaction which takes place.

Ans-

When ethanol in test tube in which drop by drop add 5% alkaline potassium permaganates solution and warm it, the purple color of potassium permanganate disappear and product form by Ethanoic acid.

 

(b) How would you distinguish experimentally between an alcohol and a carboxylic acid on the basis of a chemical property ?

Ans: A carboxylic acid reacts with sodium hydrogen carbonate to give brisk effervescence of carbon dioxide gas but an alcohol does not react with sodium hydrogen carbonate

 

30) Name the functional group of organic compounds that can be hydrogenated. With the help of a suitable example, explain the process of hydrogenation, mentioning the conditions of the reaction and any one change in physical property with the formation of the product. Name any one natural source of organic compounds that are hydrogenated.

Ans: Alkenes and alkynes are the functional group of organic compounds that can be hydrogenated.

Hydrogenation process :  when the addition of hydrogen to an unsaturated hydrocarbon in presence of nickel catalysis to form saturated hydrocarbon this process is known as hydrogenation process.

When ethylene react with hydrogen in presence of Nickel catalysis under heating condition to form ethane.
The natural source of organic compounds that are hydrogenated that is vegetable oils. Vegetables oil in liquid state hydrogenated into solid form vegetable ghee.

 

31.

(a) Name the gas evolved when ethanol reacts with sodium.

Ans: when ethanol reacts with sodium the hydrogen gas evolved.

 

(b) What type of compound is formed when a carboxylic acid reacts with an alcohol in the presence of conc. H2SO4 ?

Ans: when a carboxylic acid reacts with an alcohol in the presence of conc. H2SO4 the ether compound formed.

 

(c) What will you observe when dilute ethanoic acid and dilute hydrochloric acid are put on universal indicator paper, one by one ? What does it show ?

Ans: When dilute ethanoic acid drop put on universal indicator paper ,the paper color change it turns to orange and pH is 4 according to this ethanoic acid is weak acid.
When dilute hydrochloric acid drop put on universal indicator paper ,the paper color turns to red and pH is 1 according to this hydrochloric acid is strong acid.

 

32.

(a) What type of compound is CH3COOH ?

Ans: Compound CH3COOH is carboxylic acid in which one carbonyl group (CO) and (OH) one alcoholic group present.

 

(b) What substance should be oxidised to prepare CH3COOH ?

Ans: When ethanol oxidised to prepare ethanoic acid CH3COOH.

 

(c) What is the physical state of CH3COOH ?

Ans: CH3COOH is ethanoic acid and it is liquid in state.

 

(d) State one advantage of soaps over detergents.

Ans: Soaps cannot perform a cleansing action but detergents are broadly used in cleaning purpose.

 

33) 

 

(a) What happens when ethanol reacts with ethanoic acid in the presence of a little of concentrated sulphuric acid ? Write equation of the reaction involved.

Ans: when ethanol reacts with ethanoic acid in the presence of a little of concentrated sulphuric acid the product form by ethyl ethanoate ester and this ester is sweet smelling ester.

the product form by ethyl ethanoate ester and this ester is sweet smelling ester.

 

(b) What happens when ethanol is heated with concentrated sulphuric acid at 170°C ? Write the equation of the reaction which takes place.

Ans: When ethanol is heated with concentrated sulphuric acid at 170°C the product form by ethene and water this reaction dehydration.

 

34) 

(a) What happens when ethanol is oxidised with alkaline potassium permanganate (or acidified potassium dichromate) ? Write the equation of the reaction involved.

Ans:  when ethanol is oxidised with alkaline potassium permanganate under heating condition ethanoic acid form.

CH3COOH, CH3OH, C2H5OH, HCOOH, CH3CHO Give reasons for your choice.
Ans: CH3COOH is carboxylic acid and HCOOH is acetic acid both can turn blue litmus solution red because both are acidic compound and their pH is less than 7.

 

35.
(a) Explain the process of preparation of soap in laboratory.

Ans: The process of preparation of soap in laboratory is following :

  •  Take one beakar add 20 ml castor oil in beaker.
  •  Add 30 ml 20% sodium hydroxide solution in beaker.
  •  Stir the mixture and heat it and again stirring constantly till a paste form.
  • Again add 5 to 10 gm sodium chloride stir the mixture well and cool it .
  • After cooling liquid solution convert into solid form.
  • When soap completely set then cut it into pieces it is soap bar.

 

(b) Why is common salt (sodium chloride) added during the preparation of soap ?

Ans: When common salt i.e. sodium chloride added in mixture of castor oil and hydroxide solution common salt separate from aqueous solution. when adding common salt the solubility of soap in liquid form decreases. Solution is set in solid form.

 

(c) Why is soap not suitable for washing clothes when the water is hard ?

Ans: Soap not suitable for washing clothes when the water is hard because hard water contain calcium and magnesium. When soap react with calcium and magnesium in hard water it form insoluble precipitate and is called scum. In this process more soap waste and clothes difficult to clean.

 

36. (a) What happens when methane (natural gas) burns in air ? Write the chemical equation of the reaction involved.

Ans-

When methane react with oxygen in presence of air under heating condition carbon dioxide and water vapours form.

 

(b) What happens when ethanoic acid reacts with sodium carbonate ? Write chemical equation of the reaction involved.

Ans: When ethanoic acid reacts with sodium carbonate to form by sodium ethanoate and carbon dioxide.

(c) Give a test that can be used to differentiate chemically between butter and cooking oil.

Ans: Bromine water test used to differentiate chemically between butter and cooking oil.

Procedure:

  • Take two test. Add small amount butter in one test tube and other test tube add cooking oil.
  • Both test add bromine water and observe .

Observation:

  • In bromine water cooking oil decolourise hence it is unsaturated compound.
  • In bromine water butter not decolourise hence it is saturated compound.

 

37) (a) Describe, giving equation, a chemical reaction which is characteristic of saturated hydrocarbons (or alkanes).

Ans: Substitution reaction alkane as a methane with chlorine this reaction is characteristics of saturated hydrocarbons.

When methane react with chlorine in presence of sunlight the product chloromethane and hydrochloric acid form.

 

(b) What is an oxidising agent ? Name two oxidising agents which can oxidise ethanol to ethanoic acid.

Ans: Oxidising agent is gain of electron and is reduce chemical reaction.

Potassium permanganate and potassium Dichromate this two oxidising agents which can oxidise ethanol to ethanoic acid.

 

(c) Describe one reaction of a carboxylic acid.

Ans: 

when propanoic acid is warmed with methanol in the presence of a few drops of concentrated sulphuric acid to form by methyl Propanoate ester and water form.

 

38.

(a) Write names and formulae of hydrocarbons containing a single and a double bond (one example for each). Give one characteristic chemical property of each.

Ans: Single bond containing hydrocarbon :

Ethane CH3-CH3 contain single bond . When ethane react with chlorine in presence of sunlight to form by CH3- CH2-Cl ethane chloride and tis reaction is called substitution reaction and react proceeds fast.

 

(b) What is a detergent ? Name one detergent.

Ans: Detergent is cleaning purpose substances. It is made from Sodium and potassium salt of a long alkyl chain that terminate Sulphonate group. Detergent are produced by using Synthetic resources. The example of detergent is sodium dodecyl  benzene Sulphonate.

 

(c) Why have detergents replaced soap as a washing agent ?

Ans: Hard contain calcium and magnesium at cleansing purpose in hard water calcium and magnesium with detergent and detergent are soluble . Hence detergents replaced soap as a washing agent.

 

39) 

(a) How does ethanoic acid react with sodium hydrogen carbonate ? Give equation of the reaction which takes place.

Ans: When ethanoic acid reacts with sodium carbonate to form by sodium ethanoate and carbon dioxide.

(b) Why are carbon and its compounds used as fuels for most applications ?

Ans: When Carbon burn in air in presence of oxygen most amount of heat and energy release hence carbon and its compounds used as fuels for most applications

 

(c) Which of the two is better for washing clothes when the water is hard : soap or detergent ? Give reason for your answer.

Ans: The detergent is better for washing clothes when the water is hard.

Hard contain calcium and magnesium , at cleansing purpose in hard water calcium and magnesium with detergent and detergent are soluble . Hence detergents replaced soap as a washing agent.

 

40) 

(a) What is meant by a substitution reaction ? Give an example (with equation) of the substitution reaction of an alkane.

Ans: Substitution reaction : The substitution reaction is chemical reaction in which an atom or group of atom replace by other group of atom.

Form example: when methane react with chlorine atom in presence of sunlight methyl chloride form.

 

b) How is soap made ? Write a word equation involved in soap making.

Ans:

Soap is made by when castor oil or animals fats react with sodium hydroxide under heating condition conditions then add common salt the to settle solution after cooling soap is form.

 

41) (a) How is ethanoic acid obtained from ethanol ? Write down the chemical equation of the reaction involved.

Ans: 

When ethanol in test tube in which drop by drop add 5% alkaline potassium permaganates solution and warm it, the purple color of potassium permanganate disappear and product form by Ethanoic acid.

 

(b) How would you distinguish between ethanol and ethanoic acid by chemical test ?

Ans: By using litmus test we distinguish between ethanol and ethanoic acid. Ethanoic acid us carboxylic acid when blue litmus turn blue is ethanoic acid and pH is less than 7 But litmus paper deep in ethanol no changes appear.

 

(c) Explain the formation of scum when hard water is treated with soap.

Ans: When hard water is treated with soap the sum is form because in hard water calcium and magnesium are present. When soap combined with calcium and magnesium in hard water they are insoluble and precipitation form and is called scum.

 

42) (a) What happens when methane reacts with chlorine ? Give equation of the reaction which takes place.

Ans-

When methane react with chlorine in presence of sunlight methyl chloride form and it is halogenation reaction.

(b) What is hydrogenation ? What is its industrial application ?

Ans: Hydrogenation :Hydrogenation is a process in which addition of hydrogen molecules, as an Reduction on metal

The industrial application of hydrogenation is : When Vanaspati oil hydrogenated it convert to Vanaspati ghee.

 

(c) Give any two differences between soaps and detergents.

Ans:

Soap

Detergent

Soap are biodegradable Detergent not biodegradable
Soap are form sum in hard water Detergent not form sum in hard water.

 

 

43) (a) What happens when ethanoic acid reacts with sodium hydroxide ? Write equation of the reaction involved.

Ans: CH3COOH + NaOH→CH3COONa + H2O

When ethanoic acid react with sodium hydroxide it form by sodium ethanoate and water.

 

(b) What happens when vegetable oils are hydrogenated ? Name the catalyst used.

Ans: When vegetables oil are hydrogenated it convert into vegetable ghee. This is hydrogenation process in which Nickel and palladium both catalyst used.

 

(c) What is the advantage of detergents over soaps for washing clothes ? Also state one disadvantage.

Ans: Advantage of detergent over soap for washing clothes : In hard water detergent show well cleaning action as compare to soap.

Disadvantage of detergent over soap for washing clothes : Detergent are not biodegradable bt soap are biodegradable.

 

44.

 (a) An organic compound X of molecular formula C2H4O2 gives brisk effervescence with sodium hydrogen carbonate. Give the name and formula of X.

Ans: X compound is ethanoic acid and it’s formula CH3COOH.

When ethanoic acid react with sodium hydrogen carbonate it give brisk effervescence and product form by ethanol.

 

(b) A mixture of ethyne (acetylene) and oxygen is burnt for welding. Can you tell why a mixture of ethyne and air is not used ?

Ans: The mixture of ethyne and oxygen in presence of air can not use because when ethyne burn less amount oxygen get and sooty flame produced due to incomplete combustion hence mixture of ethyne and air not used.

 

(c) Name a chemical reaction which is characteristic of unsaturated hydrocarbons (like alkenes and alkynes).

Ans: Addition reaction is characteristics of unsaturated hydrocarbons.

 

45.

(a) What is meant by an addition reaction ? Give an example (with equation) of an addition reaction of an alkene.

Ans: The compound contain double bond those react with hydrocarbons in presence of catalyst and single bond product form is called addition reaction.

When ethylene react with hydrogen in presence of Nickel catalysis under heating condition to form ethane.

 

(b) What is added to groundnut oil when it is to be converted to vanaspati ghee ?

Ans: Hydrogen gas pass through groundnut oili is converted to vanaspati ghee.

 

(c) Which of the two is better for our health : butter or vegetable oil ? Why ?

Ans: Vegetable oil is better for our health as compare to butter because in less amount fatty acids present and it is unsaturated fatty acids.

 

Long Answer Type Questions

 

46)

(b) Give any two uses of ethanoic acid.

Ans: The two uses of ethanoic acid:

  • Ethanoic acid is use for food preservation.
  • Ethanoic acid is use as laboratory reagent.

 

47)

(b) State any two uses of esters.

Ans: The two uses of ester are following:

  • Ester is use as biodiesel.
  • Ester is used in perfume.

 

48) 
(a) Name the reaction which is usually used in the conversion of vegetable oils to fats. 
Ans: Hydrogenation reaction which is used in the conversation of vegetable oils to fats.

 

49.

(a) What is a soap ? Name one soap.
Ans: Soap is a sodium salt and potassium salt of a long chain fatty acids i. e. Carboxylic acid which is use for cleaning purpose is called soap.
The example of soap is sodium stearate – C17H35COO-Na+

 

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Updated: July 30, 2022 — 2:31 pm

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