Chemistry Past Questions and Answers

A solution of calcium bromide contains 20 g dm ³ What is the molarity of the solution with respect to calcium bromide and bromide ions? [Ca = 40, Br = 80]

A 0. 1, 0 . 1
B 0. 1, 0. 2
C 0. 1, 0. 05
D 0.05, 0.1

Question 17:

The substance ZnO dissolves in sodium hydroxide solution and mineral acid solution to give soluble products in each case. ZnO is therefore referred to as

A An allotropic oxide
B An amphoteric oxide
C A peroxide
D A dioxide

Question 18:

An acid and its conjugate base

A Can neutralise each other to form a salt
B Differ only by a proton
C Differ only by the opposite charges they carry
D Are always neutral substances

Question 19:

The same current is passed for the same time through solutions of AgNO₃ and CuSO₄ connected in series. How much silver will be deposited if 1.0 g of copper is produced?
[Cu = 63.5, S = 32, O = 16, Ag = 108, N = 14]

A 1.7 g
B 3.4 g
C 6. 8 g
D 13. 6 g

Question 20:

What is discharged at the cathode during the electrolysis of copper (ll) tetraoxosulphate (VI) solution?

A Cu ²⁺ only
B H [sup][/sup]+ only
C Cu ²⁺ and H
D Cu ²⁺ and SO ^2-