NCERT Exemplar Solution Class 10 Science Chapter 3
NCERT Exemplar Solution Class 10 Science Chapter 3 Metals and Non-Metals all Questions Answer Solution. NCERT Exemplar Class 10 Science Chapter 3 Solution PDF.
NCERT Exemplar Solution Class 10 Science Chapter 3: Overview
NCERT Exemplar Solution Class 10 Science Chapter 3 |
|
Board |
NCERT |
Topic |
Exemplar Problem Solution |
Class |
10 |
Subject |
Science |
Chapter |
3 |
Chapter Name |
Metals and Non-Metals |
NCERT Exemplar Solution Class 10 Science Chapter 3 Metals and Non-Metals
Multiple Choice Questions
1) Which of the following property is generally not shown by metals?
- Electrical conduction
- Sonorous in nature
- Dullness
- Ductility
Answer:-c) Dullness
Dullness is not the property shown by the metals, but metals have the other properties of electrical conduction, sonorous and ductility.
2) ability of metals to be drawn into wires is known as
- Ductility
- Malleability
- Sonorousity
- Conductivity
Answer:-a) Ductility
Ductility is the ability of metals to be drawn into wires.
Other options are also properties of metals it does not drawn the metal into wires.
Malleability → drawn into thin sheet
Sonorous → shining property
Conductivity → electricity and heat conduction
3) Aluminum is used for making cooking utensils. Which of the following Properties of aluminum are responsible for the same ?
- Good thermal conductivity
- Good electrical conductivity
- Ductility
- High melting point
- I and II
- I and III
- II and III
- I and IV
Answer:-d) I and IV
Good thermal conductivity and high melting point has the same connection with the making of cooking utensils. But Ductility and electrical conductivity are not useful property for the cooking.
4) Which one of the following metals do not react with cold as well as hot water ?
- Na
- Ca
- Mg
- Fe
Answer:- d) Fe
Ferrous does not reacts with cold as well as hot water but it reacts with steam. While the other reacts vigorously with water.
5) Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam?
- FeO
- Fe2O3
- Fe3O4
- Fe2O3 and Fe3O4
Answer:- c) Fe3O4
Fe3O4 will obtained after prolonged reaction of iron with steam.
The reaction carried out as
3Fe + 4H2O → Fe3O4 + 4H2
6) What happens when Calcium is treated with water ?
- It does not react with water
- It reacts Violently with water
- It reacts less violently with water
- Bubbles of Hydrogen gas formed stick to the surface of calcium
- I and IV
- II and III
- I and II
- III and IV
Answer:– d) III and IV
The less vigorous reaction between the Calcium and water evolves the hydrogen gas bubbles stick to the surface.
7) Generally metals react with acids to give salt and hydrogen gas. Which of the following acids does not give hydrogen gas on reacting with metals (except Mn and Mg)
- H2SO4
- HCl
- HNO3
- All of these
Answer:- c) HNO3
Nitric acid is a strong oxidizing agent when it reacts with metals then it does not give hydrogen gas it instead gives the water.
8) The composition of aqua – regia is
- HCl : conc. HNO3 (3:1)
- HCl : Dil. HNO3 (3:1)
- HCl : Conc. HNO3 (3:1)
- HCl : Dil. HNO3 (3:1)
Answer:- C) Conc. HCl : Conc. HNO3 3:1
The perfect composition of aqua-regia is the ratio of Conc. HCl and Conc. HNO3 into 3:1. These is used to melt the gold metal.
9) Which of the following are not ionic compounds ?
- KCl
- HCl
- CCl4
- NaCl
- I and II
- II and III
- III and IV
- I and III
Answer:- b) II and III
HCl and NaCl are not ionic compounds , these are Covalent compounds.
10) Which one of the following properties is not generally exhibited by ionic compounds ?
- Solubility in water
- Electrical conductivity in solid state
- High melting and boiling points
- Electrical conductivity in molten state
Answer:-b) Electrical conductivity in solid state
Ionic compounds are not Conductors of electricity in solid state, because these are not found in solid state .
11) Which of the following metals exist in their native state in nature ?
- Cu
- Au
- Zn
- Ag
- I and II
- II and III
- II and IV
- III and IV
Answer:- c) II and IV
Au – Gold and Ag –Silver these are two metals which are present in the native state in nature , because these does are non – reactive metals.
12) Metals are refined by using different methods. Which of the following metals are refined by electrolytic refining?
- Au
- Cu
- Na
- K
- I and II
- I and III
- II and III
- III and IV
Answer:- d) III are IV
Na- Sodium and cu- copper are most reactive metals hence these are easily refined by electrolytic refining process.
13) Silver articles become black on prolonged exposure to air. This is due to the formation of
-
- Ag3N
- Ag2O
- Ag2S
- Ag2S and Ag3N
Answer:- c) Ag2S
Silver articles reacts with the moisture present in air and these leads to the formation of Ag2S which changes the colour of the silver articles to the black.
14) Galvanization is a method of protecting iron from the rusting by coating with a thin layer of
- Gallium
- Aluminium
- Zinc
- Silver
Answer:- c) zinc
The coating of thin layer of zinc is used in the process of galvanization by electrolysisto protect the iron from rusting.
15) Stainless Steel is very useful material for our life. In stainless steel, iron is mixed with
- Ni and Cr
- Cu and Cr
- Ni and Cu
- Cu and Au
Answer:- a) Ni and Cr
Iron, nickel and chromium together in pepper proportion forms the alloy known as stainless steel. These gives the steel resistance form Corrosion and strength.
16) If copper is kept open in air, it slowly loses its shining brown surface and gains a green coating. It is due to the formation of
- CuSO4
- CuCo3
- Cu(NO3)2
- CuO
Answer:- d) CuO
The layer of Copper Oxide formed gives the green coating on copper, due to the reaction of copper with atmospheric oxygen.
17) Generally metals are solid in nature. Which of the following metals is found in liquid state at room temperature ?
- Na
- Fe
- Cr
- Hg
Answer:- d) Hg
Mercury found in liquid state at room temperature.
18) Which of the following metals are obtained by electrolysis of their Chlorides in Molten state ?
- Na
- Ca
- Fe
- Cu
- I and IV
- III and IV
- I and III
- I and II
Answer:- d) I and II
Sodium and Calcium are strongly reactive metals these are obtained by refined electrolysis by refining process from their Chlorides in Molten state.
19) Generally, Non – metals are not lustrous. Which of the following non-metal is lustrous ?
- Sulphur
- Oxygen
- Nitrogen
- Iodine .
Answer:- d) Iodine
Iodine is Non- metal but it is a lustrous. It is exceptional Non-metal.
20) Which one of the following four metals would be displaced from the solution of its salts by other three metals?
- Mg
- Ag
- Zn
- Cu
Answer:- b) Ag
Ag- silver is non- reactive metal. Which is found native in nature and hence It is easily displaced from the solution of its salt.
21) 2 mL each of concentrated HCl, HNO3 and a mixture of concentrated HCl and concentrated HNO3 in the ratio 3:1 were taken in test tubes labelled as A, B, and C. A small piece of metal was put in each test tube. No change occurred in test tubes A and B but the metal got dissolved in test tube C respectively. The metal could be
- Al
- Au
- Cu
- Pt
Answer:- b) Au
Au – gold , gold is Non-reactive metal it does not easily reacts with the other solutions, but aqua- regiais a mixture of which was present in test tube C. These Aqua regia reacts with gold and dissolved it.
22) An alloy is
- An element
- A Compound
- A homogeneous mixture
- A heterogeneous mixture
Answer:- c) homogeneous mixture
An alloy is a mixture of two or more metals or a metal and a non- metal in definite proportion. And it is a homogeneous mixture.
23) An electrolytic cell consists of
- Positively charged cathode
- Negatively charged anode
- Positively charged anode
- Negatively charged cathode
- I and II
- III and IV
- I and III
- II and IV
Answer:- b) III and IV
An electrolytic cell contains a positively charged Anode and negatively charged cathode.
24) During electrolytic refining of zinc, it gets
- Deposited on cathode
- Deposited on anode
- Deposited on cathode as well as anode
- Remains in the solution
Answer:- a) deposited on cathode
In an electrolytic cell a positively charged metal moves towards the negative rode of cathode and zinc is Positively charged hence deposited on the cathode.
25) An element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts Vigorously with water. Identify the element from the following
-
- Mg
- Na
- P
- Ca
Answer:- b) Na
Sodium is soft metal it is a exception to hardness of metal . It can easily cut by knife. It is very much reactive it reacts Vigorously with water and hence stored in kerosene.
26) Alloys are homogenous mixtures of a metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents ?
- Brass
- Bronze
- Amalgam
- Steel
Answer:- d) steel
Steel is a homogeneous mixture of iron and carbon. It is a alloy in which a non – metal is present which is carbon.
27) Which among the following statements is incorrect for magnesium metal?
- It burns on oxygen with a dazzling white flame
- It reacts with cold water to form magnesium hydroxide and evolves hydrogen gas
- It reacts with hot water to form magnesium hydroxide and Evolves hydrogen gas
- It reacts with steam to form magnesium hydroxide and evolves Hydrogen gas
Answer:-b) It reacts with cold water to form magnesium hydroxide and evolves hydrogen gas
The sentence b) is incorrect because Magnesium reacts with cold water and forms the magnesium oxide not magnesium hydroxide.
28) Which among the following alloys contain mercury as one of its constituents ?
- Stainless steel
- Alnico
- Solder
- Zinc amalgam
Answer:- d) Zinc amalgam
Zinc amalgam is made up of mercury and zinc. It is a alloy of mixture of these two.
29) Reaction between X and Y, forms Compound Z. X loses electron and Y gains electron. Which of the following properties is not shown by Z?
- Has high melting point
- Has low melting point
- Conducts electricity in molten state
- Occurs as solid
Answer:- b) Has low melting point
As the Z is made up of ion exchange the compound Z is ionic compound, hence it has low melting point is wrong.
30) The electronic configurations of three elements X, Y, and Z are X – 2,8 ; Y – 2,8,7 ; Z – 2,8,2. Which of the following is correct ?
- X is a metal
- Y is a metal
- Z is a non-metal
- Y is a non-metal and z is a metal
Answer:- d) Y is a non-metal and z is a metal
The outermost shell of z contains only 2 metals hence it is electro positive and thus it is a metal , and Y is a non- metal because it has 3 electrons in its outermost shell hence electronegative.
31) Although metals form basic oxides which of the following metal form an amphoteric oxide ?
- Na
- Ca
- Al
- Cu
Answer:- c) Al
Amphoteric oxide contains both the qualities of acidic and basic . And aluminium is amphoteric.
32) Generally, non-metal are not Conductors of electricity. Which of the following is a good Conductor of Electricity ?
- Diamond
- Graphite
- Sulphur
- Fullerene
Answer:- b) Graphite
Graphite is a exception for the conductivity of electricity of non- metal. Although non- metals are bad Conductors of electricity but it is exceptional.
33) Electrical wires have a coating of an insulating material. The material, generally used is
- Sulphur
- Graphite
- PVC
- All can be used
Answer:- c) PVC
PVC i.e. polyvinyl chloride is used for the insulating the Electrical wires.
Graphite is good Conductor of Electricity thus it can not used. Also Sulphur is brittle in nature hence it cannot used.
34) Which of the following non- metals is a liquid ?
- Carbon
- Bromine
- Phosphorus
- Sulphur
Answer:- b) Bromine
Bromine is present in a liquid state while it is a non – metal.
35) Which of the following can undergo a chemical reaction?
- MgSO4 + Fe
- ZnSO4 + Fe
- MgSO4 + pb
- CuSO4 + Fe
Answer:- d) CuSO4 + Fe
On the reactivity scale iron comes before the copper hence iron can replace the copper from CuSO4, and gives the product of FeSo4.
36) Which one of the following figures correctly describes the process of electrolytic refining ?
A
B
C
D
Answer:- b)
Figure b ) shows the correct electrolytic refining process because the copper ions which are positively charged these moves towards the negatively charged cathode rode.
Short Answer Questions
1) Iqbal treated a lustrous, divalent element M with sodium hydroxide. He observed the formation of bubbles in reaction mixture. He made the same observations when this element was treated with Hydrochloric acid. Suggest how can he identify the produced gas. Write chemical equations for both the reactions.
Answer:- The reactions carried out by him are as-
M+ 2NaOH → Na2MO2 + H2
When the same reaction is carried out with HCl
Then,
M+ 2HCl → MCl2 + H2
In both the reactions Hydrogen gas is evolved these can be confirmed by bringing the gas near a burning matchstick, if the stick burns with the pop sound , then it confirms the hydrogen gas.
2) During extraction of metals, electrolytic refining is used to obtain pure metals, (a) which material will be used as anode and cathode for refining of silver metal by this process? (b) suggest a suitable electrolyte also. (c) in this electrolytic cell, where do we get pure silver after passing electric current ?
Answer:-
- The material used in the refining process of silver is impure material for anode and pure material for cathode .
- The suitable electrolyte for the refining process of silver metal will be silver sulphate or silver Nitrate.
- After passing the electric current we will get the pure silver metal on the cathode.
3) Why should the metal Sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?
Answer:-
It is easy to obtain the metal from Its oxides other than its Sulphide or carbonate form. Therefore metal Sulphides and metal Carbonates are converted into metal oxides.
4) Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg ), treated with HNO3, Hydrogen is not liberated, why?
Answer:-
Generally metal’s Reaction with Mineral acids gives Hydrogen but as HNO3 is strong oxidising agent so when metal is treated with HNO3 the hydrogen is converted into water . Hence Hydrogen does not liberated in these reactions.
5) Compound X and aluminium are used to join railway tracks, (a) identify the Compound X (b) name the reaction (c) write down its reaction.
Answer:-
- The compound X is Fe2O3.
- The reaction involved in these is known as aluminothermy. Which involves the thermic reaction.
- The equation for the reaction is as–Fe2O3 + 2Al → Al2O3 + 2Fe + heat
6) When a metal X is treated with cold water, it gives a basic salt Y with molecular formula XOH (molecular mass = 40) and liberates a gas Z which easily catches fire. Identify X,Y and Z and also write the reaction.
Answer:-
On the basis of given information –
X will be Sodium (Na)
Its basic salt will be NaOH
Thus, Y = NaOH
which has Molecular mass = 40
And the gas liberates during the reaction will be Hydrogen gas
Hence Z = H2
The reaction carried out over there is
2Na + 2H2O → 2NaOH + H2
7) A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance, whereas Z is a good Conductor of Electricity. Identify X, Y and Z.
Answer:- X may be the carbon according to the information. And as Y is the hardest natural substance of Carbon form then it will be diamond. And the Z is the good Conductor of electricity then it will be Graphite. These both are allotropic forms of carbon.
8) The following reaction takes place when aluminium powder is heated with MnO3.
3MnO3(s) + 4 Al (s) → 3 Mn (I) + 2 Al2O3(I) + Heat
- Is aluminum getting Reduced?
Answer:- No. Aluminium is not Reduced in these reaction. Aluminum is oxidized as oxygen is combined with it to form the product. i.e. Al2O3
- Is MnO2 getting oxidised ?
Answer:- No. MnO2 is reduced in these reaction. Because Oxygen gets removed from it when product form. i.e Mn
9) What are the Constituents of solar alloy? Which property of Solder makes it suitable for welding electrical wires?
Answer:- the constituents of the solder alloy are Lead and Aluminium. These solar alloy has very low melting point and hence it melts easily these property helps in the work of welding electrical wires.
10) A metal A, which is used in thermite process, when heated with oxygen gives an oxide B, which is amphoteric in nature. Identify A and B. Write down the reactions of oxides B with HCl and NaOH.
Answer:-
As per given statements,
A will be Aluminium (Al)
And , B will be Al2O3
When B is reacted with HCl , the equation for the reaction is as –
Al2O3 + 6 HCl → 2 AlCl3 + 3H2O
When B is reacted with NaOH , the equation for the reaction is as –
Al2O3 + 2NaOH → 2NaAlO2 + H2O
11) A metal that exists as a liquid at room temperature is obtained by heating it’s Sulphide in the presence of air. Identify the metal and its ore and give the reaction involved.
Answer:-
A metal which exists as a liquid at room temperature is mercury.
Mercury is obtained from its Sulphide (ore) when it is heated in the presence of air, these ore is Cinnabar.
The equation of reaction involved in the procedure is as –
2HgS + 3O2 → 2HgO + 2SO2
After the reaction HgO is again heated and these process further gives the mercury and oxygen.
Heat
2 HgO———–→ 2 Hg + O2
Thus, the mercury is obtained from its ore by these reaction.
12) Give the formulae of the stable binary compounds that would be formed by the combination of following pairs of elements.
- Mg and N2
Answer:- Mg3N2 –Magnesium Nitride
- Li and O2
Answer:- LiO2 – Lithium oxide
- Al and Cl2
Answer:- AlCl3 – Aluminum Chloride
- K and O2
Answer:- K2O – Potassium Oxide
13) What happens when
- ZnCO3 is heated in the absence of oxygen ?
Answer:-
the reaction occurs when the ZnCO3 is heated in the absence of oxygen is as follow-
ZnCO3 → ZNO + CO2
The reaction gives the product Zinc oxide and CO2 carbon dioxide .
14) A mixture of Cu2O and Cu2S is heated ?
Answer:- When the mixture of Cu2O and Cu2S is heated together then the reaction occurs as follows –
2Cu2O + Cu2S → 6 Cu+ SO2
The reaction gives the product of pure copper.
15) A non- metal A is an important Constituent of our food and forms two oxides B and C. Oxide B is toxic whereas C causes global warming
- Identify A, B and C
Answer:- A will be the Carbon.
B will be the carbon monoxide.
And C will be Carbon dioxide .
- To which group of periodic table does A belong ?
Answer:-
Metal A is carbon. And carbon belongs to the group 14 of the modern periodic table.
16) Give two examples each of the metals that are good Conductors and poor conductors of heat respectively.
Answer:- The examples of good conductors are –
- Aluminum
- Copper
- Iron
- Silver
- Gold
The examples of Bad Conductors are –
- Lead
- Mercury
17) Name one metal one non- metal that exist in liquid state at room temperature. Also name two metals having melting point less than 310 K (37°C)
Answer:- One metal that exists as liquid in room temperature is mercury (Hg) And One Non- metal that exist as liquid state at room temperature is Bromine (Br) . The name of the two metals which have melting point less than 310 K are Gallium and Cesium.
18) An element A reacts with water to form a Compound B which is used in white washing. The compound B on heating forms an oxide C which on treatment with water gives back B. Identify A, B and C and give the reactions involved.
Answer:- A will be the Calcium
B will be Ca(OH)2 – Calcium hydroxide
C will be CaO – Calcium oxide
The reaction involved is as –
∆
Ca(OH)2 ——-→CaO+ H2O
Calcium hydroxide Heated to give the calcium oxide and water .
19) An alkali metals A gives a compound B ( Molecular mass = 40) on reacting with water. The compound B gives a soluble Compound C on treatment with aluminium oxide. Identify A, B, and C and give the reaction involved.
Answer:- Here,
A will be Sodium
B will be Sodium hydroxide (NaOH)
NaOH has molecular mass= 40
And C will be the NaAlO2
The equation for the first reaction is given as –
2Na + 2H2O → 2NaOH + H2
Now, when it is treated with aluminum oxide,
Al2O3 + 2NaOH → 2NaAlO2 + H2O
20) Give the reaction Involved during extraction of zinc from its ore by
- Roasting of zinc ore
Answer:- the reaction of roasting of zinc ore will be carried out as –
- Calcination of zinc ore
Answer:- the reaction of Calcination of zinc ore will be carried out as –
ZnCO3 → ZnO + CO2
21) A metal M does not liberate hydrogen from acids but reacts with oxygen to give a black colour product. Identify M and black coloured product and also explain the reaction of M with oxygen.
Answer:- The metal M will be Copper ( Cu)
The black coloured product obtained after the reaction will be CuO – cupric Oxide
The reaction between M and the oxygen is carried out as –
2Cu + O2 → 2CuO
Cooper oxygen cupric Oxide
22) An element forms an oxide A2O3 which is acidic in nature. Identify A as a metal or non-metal.
Answer:- The element formed oxide which is acidic in nature hence it proves that element is A is Non – metal. Because oxides of metals are basic in nature.
23) A solution of CuSO4 was kept in an iron pot. After few days the iron pot was found to have a number of holes in it. Explain the reason in terms of reactivity. Write the equation of the reaction involved.
Answer:- When the solution of CuSO4 is kept in the iron pot the iron or ferrous which is more reactive than the copper replaced the copper from CuSO4 solution and formed FeSO4. The displacement reaction occurred there . which caused the number of holes in the pot.
Equation for the reaction is as follows –
Fe + CuSO4 → FeSO4 + Cu
Long Answer Questions
1) A non-metal A which is the largest constituent of air, when heated with H2 in 1:3 ratio in the presence of catalyst (Fe) gives a gas B. On heating with O2 it gives an oxide C. Of this oxide is passed into water in the presence of air it gives an acid D which acts as a strong oxidizing agent.
- Identify A, B, C and D
Answer:-
A = Nitrogen ( N2)
B = Ammonia (NH3)
C = Nitrogen oxide (NO)
D = Nitric acid ( HNO3)
- To which group of periodic table does this Non-metal belong?
Answer:- the Non – metal A which is Nitrogen belongs to the group 15 of the periodic table .
2) Give the steps involved in the extraction of metals of low and medium reactivity from their respective Sulphide ores.
Answer:-
The extraction of metal from its Sulphide ore is the process known as Roasting. These includes the heating of ore in the presence of oxygen, these gives out the product of metal oxides.
The steps involved in the roasting process are as follows –
Here, we will take Cinnabar which is a Sulphide ore of Mercury. Mercury is the low reactivity metal.
It will be heated in the air, the reaction is carried out as –
2HgS + 3O2 → 2HgO + 2SO2
These process gives the product mercuric oxide and Sulphur Dioxide.
The mercuric oxide is further reduced to get the pure mercury
The reaction is carried out as
2HgO + 3O2 → 2Hg + O2
- For the medium reactivity we will take the zinc ore that is zinc blend
The process of heating of zinc ore in the presence of air It will give the product of zinc oxide.
2ZnS + 3O2 → 2ZnO + 2SO2
Zinc oxide is further reduced to obtained pure zinc.
ZnO + C → Zn + Co
21) Explain the following
- Reactivity of Al decreases if it is dipped in HNO3
Answer:- The reactivity of aluminium decrease when it is dipped into nitric acid because nitric acid ( HNO3 ) is a strong oxidising agent, when aluminium is dipped in it, it oxidises and form the layer of oxides Al2O3.
- Carbon cannot reduce the oxides of Na or Mg
Answer:- The reactivity of Sodium and magnesium is higher than the reactivity of carbon, lower reactivity of elements cannot reduce the higher reactivity of elements.
- NaCl is not a Conductor of Electricity in solid state whereas it does Conduct electricity in aqueous as well as in Molten state.
Answer:- NaCl is made up of the ionic bonds , Sodium (+) and Chlorine (-) shares the ions to form the ionic bonds. In the solid state the migration of ions does not happen freely, but in aqueous state these ions move freely and hence the electricity is conducted in aqueous as well as molten state but not in rigid or solid state.
- Iron articles are galvanized.
Answer:- The iron articles get corrodes due to reaction with the atmospheric moisture. The Corrosion of iron damages the iron articles and changes its colour. To prevent the Corrosion of iron, these articles are galvanized.
- Metals like Na, K, Ca and Mg are never found in their free State in nature.
Answer:- The metals Sodium, Potassium, Calcium, And Magnesium are very highly reactive when they are placed in free State, they reacts with atmospheric gases and reacts with them.
22) Given below are the steps for extraction of copper from its ore. Write the reaction Involved.
- Roasting of copper (I) Sulphide
Answer:-
The reaction carried out during the roasting of Sulphide ore is –
∆
2Cu2O(s) + 3O2(s) —–→ 2Cu2O(s) + 2SO2(g)
When the copper Sulphide ore is heated in the presence of oxygen it gives the copper oxide and sulphur dioxide.
- Reduction of copper (I) oxide with copper (I) Sulphide.
Answer:-
The equation for the Reaction of copper(I) oxide with the Copper(I) Sulphide is –
Heat
2Cu2O + Cu2S ———→ 6 Cu + SO2
When the copper (I) oxide reacts with copper(I) Sulphide with heat it gives the product of Pure copper and Sulphur Dioxide.
- Electrolytic refining.
Answer:- The electrolytic refining contains two rode – anode and cathode.
the extraction of copper from its ore by the process of electrolytic refining,
The reaction over the cathode will be
Cu2+(aq) + 2e-→ Cu ( s)
And the reaction over the anode will be
Cu(s) → Cu2+ (aq) + 2e-
23) Draw a neat well labelled diagram for electrolytic refining of copper.
Answer:-
Diagram showing the electrolytic refining of the copper
24) Of the three metals X, Y, and Z. X Reacts with cold water, Y with hot water and Z with steam only. Identify X, Y, and Z also arrange them in order of increasing reactivity.
Answer:- Here,
X reacts with cold water hence it will be alkali metals like sodium.
Y reacts with hot water thus it will be alkaline metals like Magnesium.
Z reacts with only steam thus it will be ferrous (Fe).
Now,
Placing them into their increasing order
Na > Mg > Fe
25) An element A burns with golden flame in air. It reacts with another element B, atomic number 17 to give a product C. An aqueous solution of product C on electrolysis gives a compound D and liberates Hydrogen. Identify A, B, C and D. Also write down the equations for the reactions involved.
Answer:- Here,
A will be Sodium
B will be Chlorine
When A reacts with B then it gives the C
Hence,
A+ B = C
Thus the equation for the reaction involved is –
Na + Cl2 = 2Nacl
Thus, C is NaCl .
When the C i.e. NaCl in aqueous condition is electrolysed gives compound D and hydrogen gas.
Thus the equation for the reaction is –
2NaCl (aq) + 2H2O(l) →2NaOH(aq) + Cl2 (g) + H2 (g)
Thus, D will be NaOH .
26) Two ores A and B were taken. On heating ore A gives CO2 whereas, ore B gives SO2. What steps will you take to convert them into metals?
Answer:-
- Ore A gives Carbon dioxide on heating
Hence metal let take metal A = MCO3
The separation of metal from its Carbonate ore is takes by the process of calcination and reduction.
Hence the equation for the reaction will be as –
MCO3 —–→ MO + CO2
Calcination of MCO3 gives Metal oxide and carbon dioxide gas
MO + C → M + CO
After the oxidation metal we get
Pure metal and Carbon Monoxide.
- Ore B gives the SO2 (sulphur dioxide)
Hence we will take B as MS.
Thus, We can separate the metal from the Sulphide ore by the process of Roasting.
The equation for the roasting of Sulphide ore of metal will be given as –
2MS + 3O2 → 2MO + 2SO2
After reduction we get pure metal
MO + C → M + CO .
Here is your solution of NCERT Exemplar Class 10 Science Chapter 3 Metals and Non-Metals
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