Class 10 Chemistry

Metals and Non-metals

NCERT Exemplar Solutions

Generally, non-metals are not lustrous. Which of the following nonmetal is lustrous?

• Sulphur
• Oxygen
• Nitrogen
• Iodine
  Answer: (d) Iodine

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

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

• Al
• Au
• Cu
• Pt
  Answer: (b) Au

An alloy is

• an element
• a compound
• a homogeneous mixture
• a heterogeneous mixture
  Answer: (c) A homogeneous mixture

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) ad (iv)
  Answer: (b) (iii) and (iv)

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

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

Alloys are homogeneous mixtures of a metal with a metal or nonmetal. Which among the following alloys contain non-metal as one of its constituents?

• Brass
• Bronze
• Amalgam
• Steel
  Answer: (d) Steel

Which among the following statements is incorrect for magnesium metal?

• It burns in oxygen with a dazzling white flame
• It reacts with cold water to form magnesium oxide 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 oxide and evolves hydrogen gas