CBSE Class 10 Science Metals and Non metals Worksheet 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. The most abundant metal in the earth’s crust is
(a) Iron
(b) Aluminium
(c) Calcium
(d) Sodium

Answer: B

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

Answer: A

Question. An element X 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
(a) Mg
(b) Na
(c) P
(d) Ca

Answer: B

Question. Al2O₃ + 2NaOH → …… + H₂O
(a) Al(OH)₃
(b) Na₂O
(c) NaAlO₂
(d) AlNaO₂

Answer: C

Question. Which of the following is the correct arrangement of the given metals in ascending order of their reactivity?
Zinc, Iron, Magnesium, Sodium
(a) Zinc > Iron > Magnesium > Sodium
(b) Sodium > Magnesium > Iron > Zinc
(c) Sodium > Zinc > Magnesium > Iron
(d) Sodium > Magnesium > Zinc > Iron

Answer: D

Question. Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same?
(i) Good thermal conductivity
(ii) Good electrical conductivity
(iii) Ductility
(iv) High melting point
(a) (i) and (ii) (b) (i) and (iii)
(c) (ii) and (iii) (d) (i) and (iv)

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 property of metals is used for making bells and strings of musical instruments like Sitar and Violin?
(a) Sonorousness
(b) Malleability
(c) Ductility
(d) Conductivity

Answer: A

Question. The electronic configuration of three elements X, Y and Z are as follows: X = 2, 4 Y = 2, 7 Z = 2,1 Which two elements will combine to form an ionic compound and write the correct formula,
(a) X₂Y
(b) ZY
(c) XZ₃
(d) Y2Z

Answer: B

Question. Which of the following non-metal is lustrous?
(a) Sulphur
(b) Oxygen
(c) Nitrogen
(d) Iodine

Answer: D

Question. The atomic number of an element ‘X’ is 12. Which inert gas is nearest to X?
(a) He
(b) Ar
(c) Ne
(d) Kr

Answer: C

Question. Which of the following pairs will give dis-placement reactions?
(a) FeSO₄ solution and Copper metal
(b) AgNO₃ solution and Copper metal
(c) CuSO₄ solution and Silver metal
(d) NaCl solution and Copper metal

Answer: B

Question. Which of the 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)

Answer: B

Question. Which one among the following is an acidic oxide?
(a) Na₂O
(b) CO
(c) CO₂
(d) Al₂O₃

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 Fe₂O₄

Answer: C

Question. Composition of aqua-regia by volume is :
(a) Dil HCl (3) : Cone HNO₃ (1)
(b) Cone HCl (3) : Dil HNO₃ (1)
(c) Cone HCl (3) : Cone HNO₃ (1)
(d) Dil HC1 (3) : Dil HNO₃

Answer: C

Question. Non-metals form covalent chlorides because
(a) they can give electrons to chlorine
(b) they can share electrons with chlorine
(c) they can give electrons to chlorine atoms to form chloride ions
(d) they cannot share electrons with chlorine atoms

Answer: B

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. Example of an amphoteric oxide is:
(a) Na₂O
(b) K₂O
(c) Al₂O₃
(d) MgO

Answer: C

CASE STUDY BASED QUESTIONS:

1. Read the following and answer the questions :
On the basis of reactivity of different metals with oxygen, water and acids as well as displacement reactions, the metals have been arranged in the decreasing order of their reactivities. This arrangement is known as activity series or reactivity series of metals.
The basis of reactivity is the tendency of metals to lose electrons. If a metal can lose electrons easily to form positive ions, it will react readily with other substances. Therefore, it will be a reactive metal. On the other hand, if a meal loses electrons less rapidly to form a positive ion, it will react slowly with other substances. Therefore, such a metal will be less reactive.

Question. Which of the following represents the correct order of reactivity for the given metals?
(a) Na > Mg > Al > Cu
(b) Mg > Na > Al > Cu
(c) Na > Mg > Cu > Al
(d) Mg > Al > Na > Cu

Answer: A

Question. Which of the following metals is less reactive than hydrogen?
(a) Copper
(b) Zinc
(c) Magnesium
(d) Lead

Answer: A

Question. Which of the following elements is not present in stainless steel?
(a) Iron
(b) Chromium
(c) Tungsten
(d) Nickel

Answer: C

Question. Hydrogen gas is not evolved when a metal reacts with nitric acid. It is because HNO₃, is a strong oxidising agent. It oxidises the H, produced to water and itself gets reduced to any of the nitrogen oxides (N₂O, NO, NO₂). But _____________ and _____________ react with very dilute HNO₃ to evolve H₂ gas.
(a) Pb, Cu
(b) Na, K
(C) Mg, Mn
(d) Al, Zn

Answer: C

Question. Which of the following metals reacts vigorously with oxygen?
(a) Zinc
(b) Magnesium
(c) Sodium
(d) Copper

Answer: C

2. Read the following and answer the questions :
Metals as we know, are very useful in all fields, industries in particular. Non-metals are no less in any way. Oxygen present in air is essential for breathing as well as for combustion. Non-metals form a large number of compounds which are extremely useful, e.g., ammonia, nitric acid, sulphuric acid, etc.
Non-metals are found to exist in three states of matter. Only solid non-metals are expected to be hard however, they have low density and are brittle. They usually have low melting and boiling points and are poor conductors of electricity.

Question. Which of the following non-metals is a liquid?
(a) Carbon
(b) Bromine
(c) Iodine
(d) Sulphur

Answer: B

Question. Generally, non-metals are bad conductors of electricity but 'X'which is a form of carbon is a good conductor of electricity and is an exceptional non-metal. 'X'is
(a) diamond
(b) graphite
(c) coal
(d) coke

Answer: B

Question. ____________ is a non-metal but is lustrous
(a) Phosphorus
(b) Sulphur
(c) Bromine
(d) Iodine

Answer: D

Question. Hydrogen is used
(a) for the synthesis of ammonia
(b) for the synthesis of methyl alcohol
(c) in welding torches
(d) all of these

Answer: D

Question. Which of the following is known as 'King of chemicals'?
(a) Urea
(b) Ammonia
(c) Sulphuric acid
(d) Nitric acid

Answer: C

 

Following questions consists of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
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 (A): Hydrogen gas is not evolved when a metal reacts with nitric acid.
Reason (R): Nitric acid is a strong oxidising agent.

Answer: A

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

Answer: A

Question. Assertion(A): Magnesium chloride is an ionic compound.
Reason (R): Metals and non-metals react by mutual transfer of electrons.

Answer: A

Question. Assertion(A): MgCl₂ is a covalent compound.
Reason (R): MgCl₂is a good conductor of electricity in molten state.

Answer: D

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: The oxides of sulphur and phosphorus are acidic in nature.
Reason: Metal oxides are basic in nature.

Answer: B

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

Answer: B

Question. Assertion: Electrovalency of Na is +1.
Reason: The number of electrons which an atom either loses or gains in the formation of an ionic bond is known as its valency.

Answer: B

 

Question. When a strip of zinc metal is put in copper sulphate solution, the blue colour of copper sulphate fades gradually. Why?
Answer : When a strip of zinc metal is placed in copper sulphate solution, zinc being more reactive displaces copper from copper sulphate solution and thus colourless solution of zinc sulphate is formed. Due to formation of this colourless zinc sulphate solution, blue colour of copper sulphate fades gradually.

Question. On placing a piece of aluminium metal in the solution of mercuric chloride, it acquires a shining silvery surface but when it is placed in a solution of magnesium sulphate, no change is observed. Explain.
Answer : Aluminium is more reactive than mercury. Because of this it displaces mercury from mercuric chloride solution. This mercury deposits on the aluminium metal giving its surface silvery shining appearance. Aluminium is less reactive than magnesium. Hence, aluminium cannot displace magnesium from magnesium sulphate solution and so, no change is observed.

Question. Why does zinc react with sulphuric acid to give hydrogen gas but copper does not?
Answer : Zinc is more reactive than hydrogen. Hence, it can react with sulphuric acid to give hydrogen gas.
H₂SO₄ + Zn ⎯⎯⎯→ ZnSO₄ + H₂
Sulphuric acid Zinc Zinc sulphate Hydrogen
Copper is less reactive than hydrogen. Hence it cannot displace hydrogen from sulphuric acid.
H₂SO₄  + Cu ⎯⎯⎯→ No reaction

Question. Which of the faollowing pairs will give displacement reaction?
(i) FeSO₄ and copper metal
(ii) FeSO₄ and aluminium metal
Answer : (i) Copper metal is less reactive than iron metal, so no displacement reaction will occur between FeSO4 solution and copper metal.
(ii) Aluminium metal is more reactive than iron metal, so displacement reaction will occur between FeSO4 and aluminium metal.

Question. What would you observe when you put some aluminium pieces in copper sulphate solution?
Answer : Copper sulphate solution is blue in colour. When we put some aluminium pieces in copper sulphate solution, blue colour disappears and solution becomes colourless. As well as reddish brown deposits are seen on aluminium pieces. These changes are observed because of the following reaction.
2Al + CuSO₄ ⎯⎯⎯→ 3Cu + Al₂(SO₄)₃
White Blue Reddish brown Colourless

 

 

 

 

 

 

Ans. (i) Metal that exists in liquid state at room temperature -Mercury

 

(ii) Metal that can be easily cut with a knife -Sodium

 

(iii) Metal that is the best conductor of heat -Silver

 

(iv) Metals that are poor conductors of heat Mercury and iead.

 

 

Ans. Malleable: Substances that can be beaten into thin sheets are called malleable. For example, most of the metals are malleabe.

 

Ductile: Substances that can be drawn into thin wires are called ductile. For example, most of the metals are ductile.

 

 

Ans. Sodium and potassium are very reactive metals and combine explosively with air as well as water.   Hence, they catch fire if kept in open. Therefore, to prevent accidental fires and accidents, sodium is stored immersed in kerosene oil.