24 multiple-choice (MCQ / objective) questions from this chapter, in every exam-style shape used in the paper. Every question comes with an explanation along with the answer, so you remember why the option is correct, not just which one it is.
1 Direct Questions
Direct Questions
- 1 markWhich of the following is the most ductile metal?
(A) Silver(B) Aluminium(C) Copper(D) Gold - 1 markWhich metal is the best conductor of heat?
(A) Lead(B) Mercury(C) Silver(D) Zinc - 1 markWhich metal is found in the liquid state at room temperature?
(A) Sodium(B) Mercury(C) Gallium(D) Potassium - 1 markWhich non-metal is lustrous?
(A) Sulphur(B) Iodine(C) Oxygen(D) Phosphorus - 1 markWhat is the hardest known natural substance?
(A) Graphite(B) Quartz(C) Iron(D) Diamond - 1 markWhich of these metals can easily be cut with a knife?
(A) Iron(B) Copper(C) Sodium(D) Zinc - 1 markWhat does sodium oxide (Na₂O) form when it dissolves in water?
(A) NaCl(B) Na₂CO₃(C) NaHCO₃(D) NaOH - 1 markWhy are sodium and potassium kept immersed in kerosene oil?
(A) They are insoluble in water(B) They catch fire if left in the open(C) They change from solid to liquid(D) They are heavy - 1 markAluminium, iron and zinc form metal oxides when they react with
(A) cold water(B) hot water(C) steam(D) nothing - 1 markWhich metal reacts fastest with dilute hydrochloric acid (based on Activity 3.11)?
(A) Iron(B) Zinc(C) Magnesium(D) Aluminium - 1 markWhich acid does not usually give hydrogen gas when it reacts with a metal?
(A) Dilute hydrochloric acid(B) Dilute sulphuric acid(C) Nitric acid(D) None of these - 1 markIn what form is sodium chloride (NaCl) found in nature?
(A) As free molecules(B) As an aggregate of cations and anions(C) Only as a gas(D) Only in the molten state - 1 markIn Activity 3.8, magnesium ash dissolved in water turns red litmus paper blue, while sulphur dioxide (formed on burning sulphur) dissolved in water turns blue litmus paper red. What does this show about the two oxides?
(A) Both oxides are neutral(B) Both oxides are acidic(C) The metal oxide (MgO) is acidic and the non-metal oxide (SO₂) is basic(D) The metal oxide (MgO) is basic and the non-metal oxide (SO₂) is acidic
2 Assertion-Reason
Assertion-Reason
- 1 markAssertion (A): Aluminium oxide (Al₂O₃) is an amphoteric oxide.
Reason (R): It reacts with both acids and bases to give a salt and water.
(A) A is true, R is true, R is the correct explanation(B) A is true, R is true, R is NOT the correct explanation(C) A is true, R is false(D) A is false, R is true - 1 markAssertion (A): Copper can release hydrogen gas from dilute acids.
Reason (R): Copper lies below hydrogen in the reactivity series.
(A) A is true, R is true, R is the correct explanation(B) A is true, R is true, R is NOT the correct explanation(C) A is true, R is false(D) A is false, R is true - 1 markAssertion (A): Aluminium is a highly reactive metal, yet it is used to make cooking utensils.
Reason (R): A thin oxide layer forms on aluminium’s surface and protects it from further oxidation.
(A) A is true, R is true, R is the correct explanation(B) A is true, R is true, R is NOT the correct explanation(C) A is true, R is false(D) A is false, R is true - 1 markAssertion (A): Sodium chloride (NaCl) has a very high melting point (1074 K).
Reason (R): NaCl molecules are held together by weak forces.
(A) A is true, R is true, R is the correct explanation(B) A is true, R is true, R is NOT the correct explanation(C) A is true, R is false(D) A is false, R is true
3 Match the Following
Match the Following
- 1 markMatch Column A with Column B:
A: 1. Gold 2. Silver 3. Mercury 4. Gallium
B: (i) Liquid at room temperature (ii) Most ductile metal (iii) Melts in the palm of a hand (iv) Best conductor of heat
(A) 1-iv, 2-ii, 3-iii, 4-i(B) 1-i, 2-iii, 3-ii, 4-iv(C) 1-ii, 2-iv, 3-i, 4-iii(D) 1-iii, 2-i, 3-iv, 4-ii - 1 markMatch Column A (alloy) with Column B (composition):
A: 1. Brass 2. Bronze 3. Solder 4. Stainless steel
B: (i) Lead + tin (ii) Iron + nickel + chromium (iii) Copper + zinc (iv) Copper + tin
(A) 1-i, 2-ii, 3-iii, 4-iv(B) 1-iii, 2-iv, 3-i, 4-ii(C) 1-iv, 2-iii, 3-ii, 4-i(D) 1-ii, 2-i, 3-iv, 4-iii
4 Statement-Based Questions
Statement-Based Questions
- 1 markStatement I: When sodium is put in cold water, the hydrogen evolved immediately catches fire.
Statement II: The reaction of sodium with cold water is violent and highly exothermic.
(A) Both true, II is the correct explanation(B) Both true, II is NOT the correct explanation(C) I true, II false(D) I false, II true
5 Arrange in the Correct Order
Arrange in the Correct Order
- 1 markArrange the steps in extracting a medium-reactivity metal in the correct order: (i) reduction with carbon (ii) enrichment of the ore (iii) roasting/calcination (iv) electrolytic refining
(A) i-ii-iii-iv(B) ii-iii-i-iv(C) iii-ii-i-iv(D) ii-i-iii-iv
6 Odd One Out
Odd One Out
- 1 markPick the odd one out (based on reaction with water/steam):
(A) Silver(B) Aluminium(C) Iron(D) Zinc
7 Passage-Based Questions
Passage-Based Questions
Passage
A student took three test tubes A, B and C and placed a clean iron nail in each. Test tube A was filled with plain water and corked. Test tube B was filled with boiled distilled water, a layer of oil was poured on top, and it was corked. Test tube C was filled with dry air and anhydrous calcium chloride and corked. After a few days the nail in test tube A was found to be rusted, while the nails in B and C were exactly as before.
- 1 markAccording to the passage, which test tube’s nail rusted, and why?
(A) Test tube B, because it had oil(B) Test tube C, because it had dry air(C) Test tube A, because both air and water were present(D) None of the nails rusted
8 True / False
True / False
- 1 mark(A) The thermit reaction is highly endothermic.
(B) The thermit reaction is used to join railway tracks.
(A) A true, B true(B) A false, B true(C) A true, B false(D) A false, B false
Answer Key and Explanations
Direct Questions
- (D) Gold is the most ductile metal: about 2 km of wire can be drawn from just 1 gram of gold.
- (C) Silver and copper are the best conductors of heat; lead and mercury conduct comparatively poorly.
- (B) All metals are solid at room temperature except mercury. Gallium and caesium have very low melting points, but they stay solid at ordinary room temperature unless warmed further, such as by the palm of a hand.
- (B) Iodine is a non-metal, yet it looks lustrous: an example of the limits of physical-property classification.
- (D) Diamond is an allotrope of carbon and the hardest known natural substance; it also has a very high melting and boiling point.
- (C) Alkali metals (lithium, sodium, potassium) are soft enough to be cut with a knife.
- (D) Na₂O(s) + H₂O(l) → 2NaOH(aq): an alkali is formed.
- (B) Sodium and potassium react so fast with oxygen that they catch fire the moment they are left in the open, so they are stored under kerosene oil.
- (C) Aluminium, iron and zinc do not react with cold or hot water, only with steam, forming a metal oxide and hydrogen.
- (C) The observed order of reactivity is Mg > Al > Zn > Fe: the rate of bubbling was highest with magnesium.
- (C) Nitric acid (HNO₃) is a strong oxidising agent: it oxidises the hydrogen formed into water and is itself reduced to an oxide of nitrogen.
- (B) Sodium chloride is not found as molecules: it is found as an aggregate of oppositely charged ions (Na⁺ and Cl⁻).
- (D) Turning red litmus blue means MgO is basic; turning blue litmus red means SO₂ is acidic. This is the general rule: most metal oxides are basic and most non-metal oxides are acidic.
Assertion-Reason
- (A) A is true, and R correctly states the definition of an amphoteric oxide, so R is the correct explanation of A.
- (D) A is false: copper does not react with dilute HCl at all, no bubbles form (Activity 3.11). R is true: metals below [H] cannot displace hydrogen from a dilute acid, which is exactly why copper is unreactive here.
- (A) Both are true, and R is the direct cause of A: it is this surface oxide layer that keeps aluminium safe for everyday use.
- (C) A is true. R is false: NaCl is not found as molecules, it is an aggregate of ions held together by a strong electrostatic force, and it is this strong force that gives it a high melting point.
Match the Following
- (C) Gold: most ductile metal (ii); Silver: best conductor of heat (iv); Mercury: liquid at room temperature (i); Gallium: melts in the palm of a hand (iii). This matches option (C).
- (B) Brass: copper+zinc (iii); Bronze: copper+tin (iv); Solder: lead+tin (i); Stainless steel: iron+nickel+chromium (ii). This order is option (B).
Statement-Based Questions
- (A) Both statements are true, and II explains I: the reaction is so violent and exothermic that the heat released ignites the hydrogen as it forms. With calcium the reaction is less violent and the heat is not enough for the hydrogen to catch fire.
Arrange in the Correct Order
- (B) First the ore is enriched (gangue removed), then roasting/calcination converts it to an oxide, then reduction with carbon gives the metal, and finally refining purifies it: the correct order is ii-iii-i-iv.
Odd One Out
- (A) Aluminium, iron and zinc react with steam to form a metal oxide and hydrogen; silver does not react with water or steam at all, so it is the odd one out.
Passage-Based Questions
- (C) Only the nail in test tube A rusted, because it alone was in contact with both air (oxygen) and water. B had no dissolved air, and C had no water.
True / False
- (B) A is false: the thermit reaction is highly exothermic, not endothermic. B is true: it is used to join railway tracks and machine parts.
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