Rajasthan Board Class 10 Science Chapter 6 Solution Chemical Reaction and Catalyst RBSE Class 10 Science Solution for Chapter 6
Objective type of questions.
(1.) Conversion of —— in —– is called –
a) Oxidation
b) Reduction
c) Dissociation
d) Combination
Ans-b) reduction
(2.) A substance breaks in two simple small molecules the reaction is called-
a) Dissociation
b) Displacement
c) Oxidation
d) Reduction
Ans- a) dissociation
(3.) Substance which donate electron are called-
a) Oxidizing agent
b) Catalyst
c) Reducing agent
d) None of these
Ans- c) reducing agent
(4.) Reactions which proceed in both directions-
a) Oxidation
b) Reduction
c) Irreversible
d) Reversible
Ans- d) reversible
(5.) Those which increase rate of reaction-
a) Catalyst
b) Oxidizing agent
c) Reducing agent
d) None of these
Ans- a) catalyst
(6.) Enzymes are-
a) Negative catalyst
b) Positive catalys
c) Auto catalyst
d) Bio catalyst
Ans- d) bio catalyst
(7.) 2Mg+ O2 — 2MgO in this reaction magnesium metal is-
a) Oxidized
b) Reduced
c) Dissociated
d) Displaced
Ans-a) oxidized
(8.) The reaction which is catalysed by the product fromed-
a) Bio chemical
b) Reversible
c) Auto catalysed
d) Irreversible
Ans- c) auto catalysed
(9.) In exothermic reaction heat is-
a ) released
b) absorbed
c) soluble
d) none of these
ans- a) released
very short type questions-
(11.) What is chemical charge?
Ans-the changes in which chemical properties and compostition of substance changes and new substances are formed is called chemical charge.
(13.) how many types of catalyst are there ? writer their name.
Ans-there are two types of catalyst
a) homogeneous catalyst
b) heterogeneous catalyst
(14.) Zn+ CuSO4 — ZnSO4 + Cu
This is an example of which type of reaction?
Ans-replacement reaction.
(15.) Give an example of redox reaction.
Ans- Fe2 O3 + 3CO—– 2Fe + 3CO2
(16.) What is reversible reaction?
Ans-the reaction in which proceeds in both directions i.e reactanct from product and again product from reactant, are called reversible reaction.
(17.) What is the work of catalyst promoter and catalyst inhibitor?
Ans- catalyst promoter increases the activity of catalyst and catalyst inhibitor decreases the catalyst activity.
(18.) What is the reaction between acid and base called?
Ans- neutralization reaction
(19.) How many types of reactions are there on the basis of velocity?
Ans- addition reaction and displacement reaction.
(20.) Write an example of thermal dissociation reaction.
Ans-2H2O – 2H2 + O2
(21.) What is the work of catalyst in any reaction?
Ans- to affect the velocity of chemical reaction and increases the speed of reaction .
(22.) What is the fundamental principle a balancing of chemical reaction.
Ans- in this balancing of reaction is important in which no number of reactant and product of in equal amount.
(23.) What is redox reaction?
Ans- the reaction in which one substance is oxidizing and another is reducing it is called redox reaction.
(24.) What type of reaction is burning of coal?
Ans- composition reaction( chemical change)
(25.) What will be the pH of solution, when strong acid and strong base react?
Ans-pH of solution will be 7
Short type questions.
(26) Write difference between physical and chemical change.
Ans-
Physical change |
Chemical change |
Only physical properties of substance like state , colour, smell etc changes. |
The substance formed as a result of the chemical change is completely different in chemical properties and compostiton form the initial subsatance. |
This change is temporary |
This change is permanent. |
(27) Write one example of combination and decomposition reaction.
Ans-a) combination reaction- in these reaction simply addition is performed. Eg- C+ O2—CO2
b ) decomposition reaction- breaks the reaction eg- CuSO4 + Zn— ZnSO4 + Cu
(28.) AgNO3 + KCl —– AgCl + KNO3
Which type of reaction is this? Write the name and explain
Ans- this is the fast chemical reaction. In which silver nitrate is react with potassium chloride and formed silver chloride and potassium nitrate this is fast reaction.
(29.) Explain oxidation and reduction on the basis of electronic change.
Ans_ those reaction in which atom ,ion, or molecules donate electron are called oxidation eg. Na—Na+ + e- here sodium donates e- and oxidized to Na+ cation
Reduction- those reaction in which atom, ion, or molecule accepts electron are called reduction.
Eg. Cl- + e- —- Cl- here cholrine accept electrons and reduce to chloride ion.
(30.) What are the types of catalyst? Write their names.
Ans-on the basis of physical state there are two types of catalyst
a) Homogeneous catalyst
b) Heterogeneous catalyst
On the basis of action there are four catalyst-
a) Positive
b) Negative
c) Auto catalyst
d) Bio catalyst.
(31.) Explain the types of dissociation reactions?
Ans- photolytic dissociation- in this type of dissociation reaction compounds get energy from light and breacks into small molecules. As in these reactions, compounds dissociates in the presence of light so these is called photolytic dissociation .eg, 2HBR —- H2 + Br2.
Displacement reaction – it is also type of dissociation reaction in which displacement of atom or molecule occurs . eg. CuSO4 + Zn —– ZnSO4 + Cu.
(32.) Why some amount of ethyl alcohol is added in chloroform?
Ans- chloroform itself is oxidized bt the oxygen in air and form phosgene gas(poisonous) for slowing down the speed of this reaction therefore some quantity of ethanol is added to it.
(34.) Are these reactions possible? Write answer with reason.
a) Cu+ZnSO4 —– CuSO4 + Zn
b) Fe+ CuSO4—– FeSO4 + Cu
Ans reaction a) not possible. as from the side High reactant always replace low reactant and take their place & we know Cu is less reactant than Zn. So its no possible.
Reaction b) is possible and it is also displacement reaction because Fe is more reactive metal and Cu is less reactive, so Fe replaces Cu from CuSO4.
Essay type questions.
(34.) How many types of chemical reactions are there? Explain
Ans –the chemical change is occurs in any substance , it differs in chemical composition and properties from main substances this is called chemical change reaction. Following are they types of reactions-
a) Addition reaction- the chemical reactions in which two or more reactancts to form a single product are called addition reaction. It is also called combination reaction.eg. burning of coal, burning of maganesium ribbon, hydrogenation of ehene.
b) Replacement reaction – the chemical reaction in which atom or group of atoms present in reactant displaces atom or group of atoms of other reactant. In this reaction the bond is already breaks and some new bonds are formed.
c) Photolytic reaction- it is type of dissociation reaction, compounds get energy from light and breaks into small molecules.
d) Dissociation reaction- when a substance dissociate in two or more simple molecules reaction is called as dissociation reaction.
e) Reaction are called slow or fast reactions on the basis of velocity.
f) The reaction of an acid and base is called neutralization reaction.
g) Oxidation and reduction reactions are also there addition of electrons called oxidation and removal of hydrogen is called reduction.
h) Reversible reaction-the reaction which procced in two direction i.e reactant form product and again product form reactant is called reversible reaction.
i) Irreversible reaction- the reaction which proceeds in one direction is called irreversible reaction.
j) This are the various types of reaction.
(35.) What do you mean by oxidation- reduction ? explain with examples.
Ans- a) oxidation reaction- the reaction in which addition of oxygen or electrons or removal of hydrogen occurs is called oxidation reaction.
b)Reduction reaction- the reaction in which addition of hydrogen or electron or removal of oxygen take place is called reduction reaction.
For example-Zn+ CuSO4— ZnSO4 + Cu
In above example Zn is oxidizing to ZnSO4 and cooper sulphate is reducing in Cu
There are various types of oxidation – reduction reaction on the basis of combination and dissociation eg. S+O2—SO2 oxidation and 2MgO—Mg +O reduction.
c) On the basis of addition and reduction of hydrogen- 2H2S+O2 — 2H2O+ 2s oxidation and ehene is reduced to ethane.
d) On the basis of electropositive and electronegative element- the reaction with electropositive element are called electropositive oxidation and reduction , similarly the reaction with electronegative elements are called electronegative oxidation-reduction reaction.
(36.) What do you know about the types and properties of catalyst?
Ans- those substance which change the velocity of chemical reaction but themselves remains unchanged are called catalyst and this phenomenon is called catalysis.
There are two types of catalyst a) homogeneous catalyst- the reaction take place are in the same phase b) heterogeneous catalyst- the reaction take place are in the different phase.
There are some other types also on the basis of action-
a) Positive catalyst the catalyst which increases the rate of reaction are called positive catalyst.
b) Negative catalyst – the catalyst which decreases the rate of reaction are called negative catalyst.
c) Auto catalyst- when the product produce itself act as a catalyst and increases the verlocity then it is called auto-catalyst .
d) Bio- catalyst- the substance is used to increases the velocity of biochemical reactions are called bio-catalyst.
Properties of catalyst- 1. Increases the rate of velocity in reaction
- their chemical composition and amount do not change.
- more active at particular temperature only with change in temperature their activity affected.
(37) Write difference between
(a) Reversible and irreversible
Ans-
Reversible reaction | Irreversible reaction |
The reaction which proceed in both direction are known as reversible reaction. | The reaction which proceed in one direction is known as irreversible reaction. |
In these reaction product formed again in reactant | In these reaction product dose not formed in the reactant. |
B) catalyst promoter – catalyst inhibitor.
Catalyst promoter | Catalyst inhibitor |
The substance which when added with catalyst in the reaction mixture increases the activity of the reaction called catalyst promoter. | The substances which when added in the reaction which decreases the activity of the reaction is called catalyst inhibitor. |
Increases the rate of reaction | Decreases the rate of reaction. |
C) homogeneous catalyst – heterogeneous catalyst
Homogeneous catalyst | Heterogeneous catalyst |
When the chemical reaction performed in the same phase then it called homogeneous catalytic reaction | When the chemical reaction performed in the different phase then the reacton is called heterogeneous catalytic reaction. |
Same physical state | Different physical state. |