UNIT 8: Physical and Chemical Equilibrium - Online Test

Q1.

Match the equilibria with the corresponding conditions,

 i) Liquid Vapour

ii) Solid Liquid

iii) Solid Vapour

iv) Solute (s) Solute (Solution)

1. melting point

2. Saturated solution

3. Boiling point

4. Sublimation point

5. Unsaturated solution

Answer : Option B
Explaination / Solution:
No Explaination.


Q2. Consider the following reversible reaction at equilibrium, A + B C, If the concentration of the reactants A and B are doubled, then the equilibrium constant will
Answer : Option D
Explaination / Solution:

A + B C

KC= [C] / [A] [B]

if [A] and [B] are doubled, [C] increases 4 times to maintain KC as constant.

equilibrium constant will remain the same – option (d)


Q3.

[Co(H2O)6]2+ (aq) (pink) + 4Cl (aq) [CoCl4]2– (aq) (blue)+ 6 H2O (l)

In the above reaction at equilibrium, the reaction mixture is blue in colour at room temperature. On cooling this mixture, it becomes pink in colour. On the basis of this information, which one of the following is true ?
Answer : Option A
Explaination / Solution:

on cooling, reverse reaction predominates and the solution is pink in colour.

decrease in temperature, favours the reverse reaction ie reverse reaction is exothermic and for the forward reaction is endothermic (ΔH > 0)


Q4.

The equilibrium constants of the following reactions are :

N2 + 3H2 2NH3 ; K1

N2 + O2 2NO ; K2

H2 + ½O2 H2O ; K3

The equilibrium constant (K) for the reaction ;

2NH3 + 5/2 O2k↔ 2NO+3H2O+3H2O, will be

Answer : Option C
Explaination / Solution:



Q5.

A 20 litre container at 400 K contains CO2 (g) at pressure 0.4 atm and an excess of SrO (neglect the volume of solid SrO). The volume of the container is now decreased by moving the movable piston fitted in the container. The maximum volume of the container, when pressure of CO2 attains its maximum value will be :

Given that : SrCO3 (S) SrO (S) + CO2(g)

KP = 1.6 atm 
Answer : Option B
Explaination / Solution:

Given that KP = 1.6 atm

V1 = 20 L

V2 = ?

T1 = 400 K

T2 = 400 K

KP = PCO2

PCO2= 1.6 atm

P1 = 0.4 atm. P2 = 1.6 atm