JAMB Chemistry Past Questions & Answers - Page 229

1,141.

The approximate volume of air containing 10cm3 of oxygen is?

A.

20 cm3

B.

25 cm3

C.

50 cm3

D.

100 cm3

Correct answer is C

Volume of air containing 10 cm O2 is
(100 x 10)/(20) = 50cm3

1,142.

What is the consequences of increasing pressure on the equilibrium reaction ZnO(s) + H2(g) Zn(s) + H2O(I)?

A.

The equilibrium is driven to the left

B.

The equilibrium is driven to the right

C.

There is no effect

D.

More ZnO is produced

Correct answer is C

No explanation has been provided for this answer.

1,143.

20 cm3 of 1.0 molar NH4OH solution when neutralized with 20.05cm3 of 0.1 molar HCl liberated -102 joules of heat. Calculate the heat of neutralization of NH4OH?

A.

-51.O KJ mol-

B.

+57.3 KJ mol-

C.

+57.O KJ mol-

D.

+51.0 KJ mol-

Correct answer is A

NH4OH = 20cm of 0.1 m
NH4 + HCl → NH4Cl = H2O
Heat of Neutralization of NH4OH
= \(\frac{-102}{2}\) = -51.0 KJ mole-1

1,144.

Which of these represents a redox reaction?

A.

AgNO3 + NaCl → AgCAl + NaNO3

B.

H2S + Pb(NO3) → PbS + 2HNO3

C.

CaCO3 → CaO + CO2

D.

Zn + 2HCl → ZnCl2 + H2

Correct answer is D

No explanation has been provided for this answer.

1,145.

How many coulombs of electricity are passed through a solution in which 6.5 amperes are allowed to run for 1.0 hour?

A.

3.90 x 102 coulombs

B.

5.50 x 103 coulombs

C.

6.54 x 103 coulombs

D.

2.34 x 104 coulombs

Correct answer is D

No explanation has been provided for this answer.