CBSE Class 10 Chemistry Metals And Non Metals Worksheet Set A

Question. An element ‘X’ is yellow coloured solid, insoluble in water but soluble in carbon disulphide. It has low melting point 114.5°C. It boils at 445°C and it bums with pale blue flame forming pungent smelling gas ‘Y’ which turns moist blue litmus red and finally colourless. ‘X’ and ‘Y’ are
(a) C, CO₂
(b) N, NO₂
(c) S, SO₂
(d) I₂, I₂O₅

Answer : C

Question. Which among the following alloys contain mercury as one of its constituents? 
(a) Stainless steel
(b) Alnico
(c) Solder
(d) Zinc amalgam

Answer : D

Question. In electrolytic refining of copper, the electrolyte used is
(a) CuO
(b) Cu(OH)₂
(c) Acidified CuSO₄(aq)
(d) CuSO₄(s)

Answer : C

Question. The poorest conductor of heat among metals is
(a) Lead
(b) Mercury
(c) Calcium
(d) Sodium

Answer : A

Question. Which one of the following four metals would be displaced from the solution of its salts by other three metals ? 
(a) Mg
(b) Ag
(c) Zn
(d) Cu

Answer : B

Question. Which of the statements about the reaction, ZnO + CO → Zn + CO₂ is correct ?
(a) ZnO is being oxidised
(b) CO is being reduced
(c) CO₂ is being oxidised
(d) ZnO is being reduced

Answer : D

Question. Bauxite is mixed with cryolite so as to
(i) reduce its melting point
(ii) increase its electrical conductivity
(iii) molten cryolite acts as solvent
(iv) increase its melting point
(a) (i), (ii) and (iii)
(b) (ii), (iii) and (iv)
(c) (iii) and (iv)
(d) (i) and (i)

Answer : A

Question. 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) ? 
(a) H₂SO₄
(b) HCl
(c) HNO₃
(d) All of these

Answer : C

Question. Amalgam is an alloy of
(a) Copper and Tin
(b) Mercury
(c) Lead and Tin
(d) Copper and Zinc

Answer : B

Question. Which of the following is purest form of carbon?
(a) Diamond
(b) Graphite
(c) Fullerene
(d) Charcoal

Answer : C

Question. Metals are refined by using different methods. Which of the following metals are refined by electrolytic refining ?
(i) Au
(ii) Cu
(iii) Na
(iv) K
(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii) and (iii)
(d) (iii) and (iv)

Answer : A

Question. Which of the following ore is concentrated by Froth floatation process ?
(a) ZnCO₃
(b) ZnO
(c) ZnS
(d) Na₂S

Answer : C

Question. Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam? 
(a) FeO
(b) Fe2O₃
(c) Fe₃O₄
(d) Fe₂O₃ and Fe₃O₄

Answer : C

Question. 2 mL each of concentrated HCl, HNO3 and a mixture of concentrated HCl and concentrated HNO3 in the ratio of 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 
(a) Al
(b) Au
(c) Cu
(d) Ag

Answer : B

Question. 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 ? 
(a) Has high melting point
(b) Has low melting point
(c) Conducts electricity in molten state
(d) Occurs as solid

Answer : B

Question. Generally, metals are solid in nature. Which one of the following metals is found in liquid state at room temperature ? 
(a) Na
(b) Fe
(c) Cr
(d) Hg

Answer : D

Question. The electronic configurations of three elements X, Y and Z are X —2, 8; Y — 2, 8, 7 and Z — 2, 8, 2. Which of the following is correct ? 
(a) X is a metal
(b) Y is a metal
(c) Z is a non-metal
(d) Y is a non-metal and Z is a metal

Answer : D

Question. Which of the following metals liberate hydrogen with 5% HNO₃ ?
(i) Cu
(ii) Zn
(iii) Mn
(iv) Mg
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)

Answer : C

Question. Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents? 
(a) Brass
(b) Bronze
(c) Amalgam
(d) Steel

Answer : D

Question. An electrolytic cell consists of
(i) positively charged cathode
(ii) negatively charged anode
(iii) positively charged anode
(iv) negatively charged cathode
(a) (i) and (ii)
(b) (iii) and (iv)
(c) (i) and (iii)
(d) (ii) and (iv)

Answer : B

True or False :

Question. A negatively charged ion is known as cation. 
Answer : False

Question. The electronic configuration of a sodiumion is the same as that of the nearest inert gas helium.
Answer : False

Question. Haematite is an ore of copper. 
Answer : False

Question. When a strip of copper metal is placed in iron(II) sulphate solution, then red-brown copper metal is formed. [True/False]
Answer : False

Question. When zinc is added to a solution of iron (II) sulphate, then the greenish colour of iron sulphate solution fades gradually due to the formation of colourless zinc sulphate solution and iron is deposited on zinc. 
Answer : True

Question. The widely used method for refining impure metal is electrolytic refining.
Answer : True

Fill in the blanks.

Question. Two metals which melt when kept on the palm are ………, ……… .
Answer: Gallium, Caesium

Question. Cinnabar is an ore of _____________ .
Answer: mercury

Question. _____________ is a non-metal which is lustrous.
Answer: Iodine

Question. Two examples of metals which are poor conductors of heat are ………, ……… .
Answer: Lead, Mercury

Question. The most abundant metal in earth crust is _____________ .
Answer: Aluminium

Question. Elements can be classified as ……… and ……. .
Answer: metals, non-metals

Question. During electrolytic refining of zinc, it gets deposited on _____________ .
Answer: cathode

Question. Only one metals, _____________ is in liquid state at the room temperature.
Answer: mercury

Question. _____________ and _____________ can be easily cut with knife.
Answer: sodium, pottassium

Question. The extraction of metals from their ores and then refining them for use is known as ……… .
Answer: metallurgy

Metals And Non-Metals Assertion Reason Class 10 Science  

A. Both assertion and reason are true, and reason is the correct explanation of assertion.
B. Both assertion and reason are true, but reason is not the correct explanation of assertion.
C. Assertion is true but reason is false.
D. Assertion is false and reason is true.

Question. Assertion: On reacting with water, calcium starts floating over water.
Reason: Calcium reacts with cold water at room temperature.

Answer: B

Question. Assertion: The reaction of calcium with water is less violent in comparison to that of sodium.
Reason: The heat evolved is not sufficient for the hydrogen to catch fire.

Answer: B

Question. Assertion: C and N do not react with dil. HCl and dil. H₂SO₄.
Reason: Metals do not react with dil. HCl and dil. H₂SO₄.

Answer: C

Question. Assertion: The property of beating a metal into sheets is called ductility.
Reason: Gold and silver are most malleable metals.

Answer: D

Question. Assertion: Silver and gold do not react with oxygen even at high temperatures.
Reason: Silver and gold are less active metals.

Answer: A

Question. Assertion: MgO exists in liquid state.
Reason: The electrostatic forces of attraction between Mg²⁺ and 0^2- ions constitute ionic bond.

Answer: D

Question. Assertion(A): Zinc oxide is amphoteric in nature.
Reason (R): Zinc oxide reacts with both acids and bases.

Answer: A

Question. Assertion: Gold occurs in native state.
Reason: Gold is a reactive metal.

Answer: C

Question : A piece of granulated zinc was dropped into copper sulphate solution. After sometime the colour of the solution changed from blue to colourless. Why? 

Answer : Zinc is above copper in the reactivity series, so zinc is more reactive than copper, hence Zinc displaces copper from its (copper's) salt solution.

CuSO₄ + Zn  → ZnSO₄ + Cu

The colour of CuSO₄ solution was blue, which changed to colourless due to formation of ZnSO₄ solution, which is colourless.

 

Question : Why are noble gases unreactive? 

Answer : Elements of group 0 are called noble gases. These elements have stable arrangements of electrons in their outermost shell. The chemical reactivity of a group highly depends on the number of electrons in the outermost shell. A stable element generally has 8 electrons in their outermost shell with some exceptions of elements with higher atomic masses and helium. If the element has less than 8 and greater than 4 electrons in their outermost shell of the valence shell it will undergo a chemical reaction to gain some electrons from a different element whereas if it has less than four electrons in the valence shell it tends to lose them all in order to gain a stable state.

However, in case of noble gases or group 0 elements the outermost shell contains 8 electrons (2 in case of Helium) which is a stable state configuration. Hence, they are chemically unreactive or inert.

 

Question : You are given a hammer, a battery, a bulb, wires and a switch. 

i. How could you use them to distinguish between samples of metals and nonmetals.

ii. Assess the usefulness of these tests in distinguishing between metals and nonmetals.

Answer : i. Set up the electric circuit as shown ahead :

Insert the sample to be tested between clips A and B If the bulbs glows, the sample is metal. If the bulb does not glow, the sample is non-metal. Thus metals are good conductors of electricity whereas non-metals are poor conductors of electricity.

ii. If a substance produces a sound when struck beating with hammer, it is a metal and if no sound is produced, it is a non-metal. Metals are sonorous whereas nonmetal are non-sonorous.

 

 

Question : Royal water is prepared by mixing two acids A and B. It can dissolve gold and platinum. It is highly corrosive and fuming liquid. Identify A and B. What is the ratio in which A and B are mixed? 

Answer :  The royal water called aqua regia is the mixture of 3 parts of HCl and 1 part of HNO₃.

It is used by the jewellers to clean the gold ornaments.

 

Question :  i. Hydrogen is not a metal but it has been assigned a place in the reactivity series of metals. Explain.

ii. How would you show that silver is chemically less reactive than copper? 

Answer : i. Though hydrogen is not a metal but even then it has been assigned a place in the activity series. The reason is that like metals, hydrogen also has a tendency to lose electron and forms a positive ion H⁺.

The metals which lose electrons less readily than hydrogen are placed below it and the metals which lose electrons more readily than hydrogen are placed above it in the reactivity series of metals.

ii. By displacement reaction silver can be shown to be chemically less reactive than copper or copper is more reactive than silver. If a piece of silver is immersed in a solution of copper sulphate, no reaction will take place because silver is less reactive than copper and will not displace copper from the copper sulphate solution.

On the other hand, if a copper plate is placed in a solution of silver nitrate, copper will slowly displace silver from the solution and blue solution of copper nitrate is formed.

This shows that copper is more reactive than silver. 

 

Question :  Which oxide of iron can be obtained on prolonged reaction of iron with steam? 

Answer :

 

Question : Name an ore of zinc other than zinc oxide. By what process this ore be converted into zinc oxide? 

Answer :  Another ore of zinc is zinc blend (ZnS). Zinc blend is converted into zinc oxide by the process of roasting in air.

Another ore of zinc is Calamite (ZnCO₃). It can be converted into zinc oxide by the process of calcination.

 

Question : Solid sodium chloride does not conduct electricity whereas molten sodium chloride conducts electricity. Explain. 

Answer : The electrical conductivity of sodium chloride is due to the movement of Na⁺ and Cl ions. In the solid state, the ions cannot move. Therefore, sodium chloride does not conduct electricity in the solid state. In the molten state, the ions are free to move.

Therefore, sodium chloride conducts electricity in the molten state.

 

Question : i. Name the metal which does not stick to glass?

ii. Name the non-metal which is a good conductor of electricity?

iii. Name the metal which is commonly used in thermit welding?

iv. What gets deposited at the cathode, a pure or impure metal?

v. hat is the nature of Zinc oxide? 

Answer :  i. Mercury

ii. Graphite

iii. Aluminum

iv. A pure metal is always deposited at the cathode

v. Zinc oxide ( ZnO) is an amphoteric oxide.

Question. Which of tire following are not ionic compounds?
(i) KCl
(ii) HCl
(iii) CCl₄
(iv) NaCl
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iii)

Question. Why are electrical wires covered with PVC? 
Answer: PVC acts as insulator, therefore, electric wires are coated with plastic so that we do not get electric shock on touching wires.

Question. Name the metal which reacts with a very dilute HNO3 to evolve hydrogen gas. 
Answer: Magnesium.

Question. Reaction of metal with dilute acid is exothermic or endothermic process?
Answer: Exothermic process.

Question. In which physical state non-metals are found?
Answer: Solid, liquid, gas.

Question. Give most suitable word for the following statements:
(a) Metal oxides which show acidic as well as basic behaviour.
(b) Iodine, a shining non-metal. 
Answer: (a) Amphoteric
(b) Lustrous

Question. An element forms an oxide, A2O3 which is acidic in nature. Identify A as a metal or non-metal.
Answer: ‘A’ is non-metal as non-metallic oxides are acidic in nature.

Question. Copper does not react with dil. HCl and dil. H2SO4 why?
Answer: Because it is less reactive than hydrogen.

Question. Name the property due to which metal produces sound?
Answer: Sonorous

Question. When metal reacts with nitric acid, H2 is not evolved why?
Answer: HNO₃ is good oxidising agent, therefore, it oxidises H2 to H2O and itself gets reduced to N2O, NO and NO2 depending upon concentration of acids.

Question. What is metallic lustre?
Answer: Most of metals have shiny surface i.e. they show metallic lustre e.g. Au, Ag, Pt are lustrous.

Question : An element forms an oxide A₂O₃ which is acidic in nature. Identify A as a metal or non- metal. 
Answer :  Metals usually form basic oxides like BaO, MgO, Na₂O etc. Unlike metals, non-metals tend to form acidic oxides. Since an oxide of element is acidic in nature, therefore, A will be a non-metal. The formula for oxide is A₂O₃, which means the charge on the element must be +3 or the element should have 3 valence electrons. This implies that the element is boron and the formula for oxide would be B₂O₃

 

 

 

Question. An alloy can be one of the following types:
(a) Homogenous
(b) Heterogeneous
(c) Intermetallic
(d) All of the above

Answer : A

Question. A student adds some metallic ash in water taken in a test tube. The ash gets completely dissolved in water and the solution changes its colour. What should the student do next to test the chemical properties of the product formed?
(a) Evaporate the solution to get crystals.
(b) Measure the temperature change using a thermometer.
(c) Test the acidity using a blue litmus paper.
(d) Test the basicity using a red litmus paper.

Answer : D

Question. Galvanisation is a method of protecting iron from rusting by coating with a thin layer of
(a) Gallium
(b) Aluminium
(c) Zinc
(d) Silver

Answer : C

Question. The atomic number of an element X is 20. The number of electrons in its ion X2+ will be:
(a) 18
(b) 19
(c) 20
(d) 21

Answer : A

Question. Which of the following metals exist in their native state in nature?
(i) Cu (ii) Au (iii) Zn (iv) Ag
c (i) and (ii)
(b) (ii) and (iii)
(c) (ii) and (iv)
(d) (iii) and (iv)

Answer : C

Question. In stainless steel alloy, iron metal is mixed with:
(a) Cu and Cr
(b) Cr and Ni
(c) Cr and Sn
(d) Cu and Ni

Answer : B

Question. Rusting of iron takes place in
(a) Ordinary water
(b) Boiled water
(c) Both ordinary & boiled water
(d) None of these

Answer : A

Question : Out of three metals P, Q and R, P is less reactive than Q and R is more reactive than P and Q both. Suggest an activity to arrange P, Q and R in order of their decreasing reactivity. 
Answer :   (A) Take salt solutions, say sulphate solutions, of metals P and Q in separate test tubes.
(B) Put a strip of metal R in both the test tubes.
(C) The solution becomes colourless in both the test tubes which shows that metal R displaces P and Q ions from their solutions.
(D) Next, put a strip of metal P in the test tube containing salt solution of metal Question :
(E) No reaction takes place as P cannot displace Q ions from its solution. The decreasing order of reactivity of given metals is : R > Q > P

Question : State five uses each of metals and non- metals.
Answer :   Uses of metals:
(A) Lead metal is used in making car batteries.
(B) Zinc is used for galvanizing iron to protect it from rusting.
(C) Iron, copper and aluminium are used to make utensils.erials.Uses of non-metals:
(A) Hydrogen is used in the hydrogenation ofvegetable oils.
(D) Copper and aluminium metals are used to make electrical wires.
(E) Aluminium is used to make aluminium foil for packaging mat
(B) Carbon is used to make electrodes ofelectrolytic cells and dry cells.
(C) Nitrogen is used in the manufacture of ammonia, nitric acid and fertilizers.
(D) Sulphur is used for producing sulphuric acid.
(E) Liquid hydrogen is used as rocket fuel.

Question : Rohan observed that if a small piece of sodium is added to water, it catches fire, whereas a piece of calcium added to the water does not catch fire. Can you explain his observations with the help of the chemical equations?
Answer :  Sodium reacts vigorously with cold water, forming sodium hydroxide and hydrogen gas. The chemical reaction is as follows:
2Na + 2H₂O → 2NaOH + H₂(g)↑ + Heat
Sodium Water Sodium Hydrogen hydroxide
The reaction of sodium metal with water releases a large amount of heat, due to which the hydrogen gas formed during the reaction catches fire easily. Thus, sodium is a very reactive metal.
On the other hand, calcium reacts with cold water to form calcium hydroxide and hydrogen
gas. The chemical reaction is as follows:
                                  Ca       +       2H₂O      →       Ca(OH)₂ ↓     +  H₂
                               Calcium            Water                Calcium            Hydrogen
                                                                             hydroxide
The heat produced in this reaction is less. It is not sufficienttoburnthehydrogengasformed. The reaction of calcium metal with water is less violent as compared to sodium. So, we can say that calcium is less reactive than sodium.

Question : Name the following:
(A) Metal that can be cut by knife
(B) Lustrous non-metal
(C) Metal that exists in liquid state at room temperature
(D) Most malleable and ductile metal
(E) Metal that is best conductor of electricity
(F) Non-metal that can exist in different forms
Answer :  (A) Metal which can be cut by knife—Sodium
(B) Lustrous non—metal—Iodine
(C) Metal that exists in liquid state at room temperature—mercury
(D) Most Malleable and ductile metal—Gold
(E) Metal that is best conductor of electricity— Silver
(F) Non-metal that can exist in different forms—Carbon

Question : A solution of CuSO₄ was kept in an iron pot. After a 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 :  In reactivity series, iron is placed above copper. So, we can say that iron is more reactive as compared to copper and it can displace copper from its compounds.
When copper sulphate solution is placed in an iron pot, iron reacts with copper sulphate andforms iron sulphate with copper.
                                                               Fe + CuSO₄ → FeSO₄ + Cu
So, the blue colour of copper sulphate solution fades to light green due to the formation of iron sulphate and holes are produced at places where iron metal has reacted. 

Question : An ore on heating in air produces sulphur dioxide. Which process would you suggest for its concentration? Describe briefly any two steps involved in the conversion of this concentrated ore into related metal. 

Answer :  The ore on heating produces sulphur dioxide gas so it is a sulphide ore. The method used for its concentration is "froth floatation process". After concentration of the ore following two steps would be followed to convert it into metal.

(i) Roasting: The sulphide ore is converted into its oxide by heating it in the presence of air.

(ii) Reduction of metal oxide to metal: The oxide formed by roasting is then reduced to metal by using a suitable reducing agent like carbon (coke).

i. Does the bulb glow? What does this indicate?

ii. Why are electric wires coated with rubber like materials?

Answer :  i. Yes the bulb glows, this indicates that metal is a good conductor of electricity.

ii. Rubber like substance is a bad conductor of electricity and prevents from electric shock.

 

 

Question : How is copper obtained from its ore (Cu₂S)? Write only the chemical equations. How is copper thus obtained refined? Name and explain the process alongwith a labelled diagram. 

Answer :  Copper is obtained from its ore Copper glance (Cu₂S) in two steps: 

The Copper thus obtained is refined by the process called "Electrolytic Refining". In this, the impure copper is made anode by connecting to the positive terminal of the battery and a thin plate of pure copper is made cathode by connecting to the negative terminal of the battery. The copper sulphate(acidified) solution is taken in the tank which acts as an electrolyte. When an electric current is passed through the solution, the pure copper from the anode passes into the solution and an equivalent amount of Cu⁺ ions from the solution are deposited on the cathode as pure copper. Impure copper usually contains the impurities (Fe, Ag, Au) which collects below the anode as "Anode mud".

At cathode : Cu²⁺(aq) + 2e^-  →Cu(s)

At anode : Cu(s) → Cu²⁺(aq)+ 2e^-

The diagram shown below is of electrolytic refining of copper