Chemistry MCQs Class 9 – Page 18 – Quiz | Online MCQs Test

Which of the following is the reaction taking place at anode?

(A) 2H_{2 (g)}+O_{2 (g)} → 2H₂O_(I)
(B) Zn⁺²_(aq) + 2e^– → Zn_(s)
(C) Cr_(s)→ Cr^{+3 (aq)} + 3e^-3
(D) Pb_(s) + Cl_2(g) → PbCl_2(s)

Answer: (C) Cr_(s)→ Cr^{+3 (aq)}+ 3e^-3

Gain of electrons and loss of oxygen is called:

(A) Oxidation
(B) Reduction
(C) Redox reaction
(D) Neutralization reaction

Answer: (B) Reduction

A chemist dissolves 15 g of NaCl in 85g of H2O. This solution is:

(A) 85% m/m NaCl solution
(B) 15% m/v NaCl solution
(C) 15% v/v NaCl solution
(D) 15% m/m NaCl solution

Answer: (D) 15% m/m NaCl solution

An aqueous solution can dissolve 25 g of a solid at 25°C. If someone dissolves 20 g of this solid in water at 25°C then this solution will be called:

(A) Supersaturated solution
(B) Unsaturated solution
(C) Saturated solution
(D) Solution of liquid

Answer: (B) Unsaturated solution

The direct conversion of a solid into vapours is called:

(A) Evaporation
(B) Melting
(C) Boiling
(D) Sublimation

Answer: (D) Sublimation