Application of Equilibrium Constant

IMPORTANT

Application of Equilibrium Constant: Overview

This topic covers concepts, such as, Applications of Equilibrium Constants, Predicting Direction of Reaction, Vapour Pressure and Determination of Relative Humidity & Average Molar Mass of Equilibrium Mixture etc.

Important Questions on Application of Equilibrium Constant

EASY
IMPORTANT

When two reactants, A and B are mixed to give products C and D, the reaction quotient Q, at the initial stage of the reaction :–

EASY
IMPORTANT

When two reactants A and B are mixed to give products C and D, the reaction quotient Q at the initial stage of the reaction is best described by-

MEDIUM
IMPORTANT

Phosphorus pentachloride dissociates as follows, in a closed reaction vessel,   PCl 5 (g)   PCl 3 (g) + Cl 2 (g)

If total pressure at equilibrium of the reaction mixture is P and degree of dissociation of   PCl 5 is x, the partial pressure of   PCl 3 will be :

MEDIUM
IMPORTANT

The vapour density of a sample N2O4g is 40 at 10 atm. Calculate the KP for the reaction.

MEDIUM
IMPORTANT

The degree of dissociation of acetic acid in a 0.1 N solution is 1.32×10-2. At what concentration of nitrous acid will its degree of dissociation be the same as that of acetic acid?

Ka for HNO2 = 4 × 10-4

(Report your answer by multiplying the value with 10)

MEDIUM
IMPORTANT

At what concentration of the solution will the degree of dissociation of nitrous acid be 0.2?

 (Ka for HNO2 is 4×10-4)

Report the value by multiplying with 1000 and rounding off to one significant figure.

MEDIUM
IMPORTANT

Calculate the percentage degree of ionisation of 0.4 M acetic acid in water. Dissociation constant of acetic acid is 1.8×10-5.

Give your answer by multiplying the value with 1000.

HARD
IMPORTANT

HI is introduced into three identical 500 mL bulbs at 350°C. Each bulb is opened at different time intervals and analysed for I2 by titrating with 0.015 M hypo solution.

I2+2Na2S2O3Na2S4O6+2NaI

0.3 g
Bulb number Initial mass of HI Time of opening bulb Vol. of hypo required
1 0.3 g 2 20.96 mL
2 0.406 g 20 41.50 mL
3 0.28 g 40 28.68 mL

 Kc for 2HIH2+I2 at 350°C is y2×10-2

Express the y value after rounding off up to nearest integer.

HARD
IMPORTANT

5 moles of SO2 and 5 moles of O2 react in a closed vessel. At equilibrium 60% of the SO2 is consumed. The total number of gaseous moles (SO2, O2 and SO3) in the vessel is:

MEDIUM
IMPORTANT

0.6 mole of PCl5, 0.3 mole of PCl3 and 0.5 mole of Cl2 are taken in a 1L flask to obtain the following equilibrium:
PCl5(g)PCl3(g)+Cl2(g)
If the equilibrium constant Kc for the reaction is 0.2. Predict the direction of the reaction.

MEDIUM
IMPORTANT

2A+B3C, KC=49

For the above reaction, 3 L vessel contains 2, 1 and 3 moles of A, B and C respectively. Then, what will happen to the reaction?

MEDIUM
IMPORTANT

The reaction quotient Q predicts:

EASY
IMPORTANT

For a reaction A products, the value of equilibrium constant 'K', when the reaction reaches completion, would be close to which among the following?

EASY
IMPORTANT

For the reaction at 27°C

MgCO3sMgOs+CO2; KP=100 atm

If 42 g of  MgCO3 is taken in 20 L vessel then calculate percentage dissociation of MgCO3

[Take : R=0.08 L atm mol-1 K-1]

MEDIUM
IMPORTANT

For the reaction; A+B3C, at 25°C, a 3 litre vessel contains 1,2,4 moles of A,B and C respectively. If Kc, for the reaction is 10, the reaction will proceed in:

MEDIUM
IMPORTANT

The equilibrium constant for a gaseous reaction is KC=[HI]H2I2. The correct balanced equation for expression is :

HARD
IMPORTANT

Fe2O3s may be converted to Fe by the reaction :-

Fe2O3s+3H2g2Fes+3H2Og

for which KC=8 at temp. 720°C
What percentage of the H2 remains unreacted after the reaction has come to equilibrium ?

EASY
IMPORTANT

At 500 K, the equilibrium constant for the reaction: H2(g)+I2(g)2HI(g) is 25. If 12 mol/L of HI is present at equilibrium, what are the concentrations of H2 and I2, assuming that we started by taking HI and reached the equilibrium at 500 K ?

HARD
IMPORTANT

Ag+3Bg2Cg+Dg Initial moles of A is twice that of B. If at equilibrium, moles of B&C are equal, then % of B reacted will be :

MEDIUM
IMPORTANT

Ag+3 Bg2Cg+Dg Initial moles of A is twice that of B. If at equilibrium, moles of B & C are equal, then % of B reacted will be :