Stoichiometry MCQs

Question 1

Average molecular weight of air is about

Accepted Answer

29

Answer

21

Answer

23

Answer

79

Question 2

During a phase change process like sublimation, vaporisation, melting etc., the specific __________ does not change.

Accepted Answer

Gibbs free energy

Answer

Enthalpy

Answer

Internal energy

Answer

Entropy

Question 3

Heat of neutralisation of HCl and NaOH is - 57.46 kJ/Kg mole. The heat of ionisation of water will be __________ kJ/Kg mole.

Accepted Answer

57.46

Answer

-57.46

Answer

114.92

Answer

-28.73

Question 4

In case of a solution (not of a solid in a liquid), whose total volume is less than the sum of the volumes of its components in their pure states, solubility is

Accepted Answer

Increases with rise in pressure

Answer

Independent of temperature

Answer

Increased with decrease in pressure

Answer

Unchanged with pressure changes

Question 5

40 gms each of the methane and oxygen are mixed in an empty container maintained at 40°C. The fraction of the total pressure exerted by oxygen is

Accepted Answer

$$\frac{1}{3}$$

Answer

$$\frac{1}{2}$$

Answer

$$\frac{1}{4}$$

Answer

$$\frac{2}{3}$$

Question 6

The density of a liquid is 1500 kg/m 3 . Its value in gin/litre will be equal to

Accepted Answer

1500

Answer

1.5

Answer

15

Answer

150

Question 7

For a neutral solution (pH = 7), the value of [H + ] [OH - ] is equal to

Accepted Answer

1

Answer

0

Answer

< 1

Answer

> 1

Question 8

With rise in pressure, the solubility of gases in solvent, at a fixed temperature

Accepted Answer

Increases

Answer

Decreases

Answer

Remains unchanged

Answer

Decreases linearly

Question 9

Pick out the wrong statement.

Accepted Answer

A supersaturated solution of a sparingly soluble solute, at a concentration of C, is being fed to a crystalliser at a volumetric flow rate of V. The solubility of the solute is C 1 . The output rate of solids from an efficient crystalliser is (C + C 1 )V

Answer

To make 100 kg of a solution containing 40% salt by mixing solution A (containing 25% salt) and solution B (containing 50% salt), the amount of solution A required is 40 kg

Answer

1.2 gm atoms of carbon and 1.5 gm moles of oxygen are reacted to give 1 gm mole of carbon dioxide. The limiting reactant is carbon. The percent excess reactant supplied is 25

Answer

A gas bubble at a pressure of P g is passed through a solvent with a saturation vapour pressure of P s . If the time of passage of the bubble is long and air is insoluble in the solvent, the mole fraction of solvent in the bubble will be equal to $$\frac{{{{	ext{P}}_{	ext{s}}}}}{{{{	ext{P}}_{	ext{g}}}}}$$