Metals and Non-metals MCQ 1
10. Which one of the following properties is not generally exhibited by ionic compounds?
(a) Solubility in water
(b) Electrical conductivity in solid state
(c) High melting and boiling points
(d) Electrical conductivity in molten state
Ans. (b) Electrical conductivity in solid state
Explanation: Free ions are required for electrical conductivity. In ionic compounds, free ions are not available in solid state.
11. Which of the following metals exist in their native state in nature?
(i) Cu
(ii) Au
(iii) Zn
(iv) Ag
(a) (i) and (ii) (b) (ii) and (iii)
(c) (ii) and (iv) (d) (iii) and (iv)
Ans. (c) (ii) and (iv)
Explanation: Gold and silver are noble metals and are the least reactive metals. Hence, they are found in their native state in nature
12. 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)
Ans. (d) (iii) and (iv)
Explanation: These metals are at the top of reactivity series. Hence, these are refined by electrolytic refining.
13. Silver articles become black on prolonged exposure to air. This is due to the formation of
(a) Ag3N
(b) Ag2O
(c) Ag2S
(d) Ag2S and Ag3N2
Ans. (c) Ag2S
14. Galvanisation is a method of protecting iron from rusting by coating with a thin
layer of
(a) Gallium
(b) Aluminium
(c) Zinc
(d) Silver
Ans. (c) Zinc
Explanation: Applying a layer of zinc through electrolysis is called galvanization.
15. Stainless steel is very useful material for our life. In stainless steel, iron is mixed with
(a) Ni and Cr
(b) Cu and Cr
(c) Ni and Cu
(d) Cu and Au
Ans. (a) Ni and Cr
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
(a) CuSO4
(b) CuCO3
(c) Cu(NO3)2
(d) CuO
Ans. (d) CuO
Explanation: When kept in open air, Copper reacts with oxygen to form copper oxide which appears as greenish layer.
17. 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
Ans. (d) Hg
Explanation: Mercury is the metal which is present in liquid state at room temperature.
18. Which of the following metals are obtained by electrolysis of their chlorides in molten state?
(i) Na
(ii) Ca
(iii) Fe
(iv) Cu
(a) (i) and (iv)
(b) (iii) and (iv)
(c) (i) and (iii)
(d) (i) and (ii)
Ans. (d) (i) and (ii)
Explanation: These metals are at the top of reactivity series.
19. Generally, non-metals are not lustrous. Which of the following non-metal is
lustrous?
(a) Sulphur
(b) Oxygen
(c) Nitrogen
(d) Iodine
Ans. (d) Iodine
20. 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
Ans. (b) Ag
Explanation: Silver is the least reactive metal among the given metals.
21. 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) Pt
Ans. (b) Au
Explanation: Mixture in test tube C is called Aqua Regia. It dissolves gold.
22. An alloy is
(a) an element
(b) a compound
(c) a homogeneous mixture
(d) a heterogeneous mixture
Ans. (c) A homogeneous mixture
Explanation: Components of alloy retain their chemical properties; hence alloy cannot be a compound. Composition of alloy is uniform; hence it is a homogeneous mixture.
