Application of Equilibrium Constant

IMPORTANT

Application of Equilibrium Constant: Overview

This topic covers concepts such as Degree of Dissociation for Equilibrium Reactions, Calculating Reaction Quotient, Applications of Equilibrium Constants, Predicting Direction of Reaction, Predicting Extent of Reaction, Reaction Quotient(Q), 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 :–

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 :

EASY
IMPORTANT

Consider three vessels containing aqueous solutions of a weak acid HA (initial concentration C1, degree of dissociation α1 ), another weak acid HB (initial concentration C2, degree of dissociation β2 ), and their mixture (initial concentration of HA=C1, degree of dissociation α3 and initial concentration of HB=C2, degree of dissociation β3 ), respectively. When C1 and C2 are varied, the correct plot (assuming α and β to be small) is

HARD
IMPORTANT

N2O4(g)2NO2(g), Kc=4.   

The above reaction is studied graphically as shown in the figure.

Question Image

 Which of the following statements are correct?

MEDIUM
IMPORTANT

COCl2 gas dissociates according to the equation, COCl2COg+Cl2g. When heated to 700 K the density of the gas mixture at 1.16 atm and at equilibrium is 1.16 g/litre. The degree of dissociation of CO2 at 700 K is

MEDIUM
IMPORTANT

When the reaction A+2B2C+D was studied, it was observed that the initial concentration of B was 1.5 times that of A, and the equilibrium concentrations of A and C were equal. Then Kc for the given equilibrium equals

MEDIUM
IMPORTANT

Identify the correct expression for the equilibrium constant of the following reaction:
2X(g)+Y(g)3Z(g)

EASY
IMPORTANT

N2O4g2NO2g; Kc=5.7×10-9 at 298 K. At equilibrium

EASY
IMPORTANT

If Kc is very large 

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:

MEDIUM
IMPORTANT

In an aqueous solution of volume 500 mL, when the reaction of 2Ag++CusCu2++2Ags reached equilibrium the Cu2+ was xM. When 500 mL of water is further added, at the new equilibrium Cu+2 will be :-

HARD
IMPORTANT

The equilibrium constant for the reaction between CH4 (g) and H2S (g) to form CS2 (g) and H2 (g), at 1173 K is 3.6. For the following composition of the reaction mixture, decide which of the following option is correct?
[CH4]=1.07 M, [H2S]=1.20 M, [CS2]=0.90 M , [H2]=1.78 M

HARD
IMPORTANT

A mixture of NO2 and N2O4 has a vapour density of 38.3 at 300 K. What is the number of moles of NO2 in 100 g of the mixture?

HARD
IMPORTANT

Column I Column II
(A)                Cu  +        2 Ag+               Cu2+      +  2 Ag Concs:             3·0×10-9 M        1·8×10-2 MEquilibrium const.=2.0×1015 (p) Reaction will shift forward
(B)                H2  +       I2                2HI  Concs. 10-2   3·0×10-2        2·0×10-2 (Moles)
Volume of vessel=2 L
Equilibrium constant=50.5
(q) Reaction will shift backward
(C)                     N2 + 3H2  2NH3Pressures 0·5     3·0         0·5 (atm)
Kp=4.28×10-5
(r) Reaction is in equilibrium
(D) PCl5  PCl3 + Cl2
Helium gas is added to the reaction mixture at equilibrium keeping the pressure constant.
(s) Reaction may shift in the forward
or backward direction.

 

MEDIUM
IMPORTANT

The equilibrium constant for the reaction between CH4 (g) and H2S (g) to form CS2 (g) and H2 (g), at 1173 K is 3.6. For the following composition of the reaction mixture, decide which of the following option is correct?
[CH4]=1.07 M, [H2S]=1.20 M, [CS2]=0.90 M , [H2]=1.78 M

HARD
IMPORTANT

The equilibrium constant for the reaction, A+2BC+D, is 1.0×108.

Calculate the equilibrium concentration of A, if 1.0 mole of A and 3.0 mole of B are placed in 1L flask and allowed to attain the equilibrium.

EASY
IMPORTANT

The equilibrium constant(K) for the reaction Cyclohexane Hex-1-ene is 10732. At the given condition in a closed one litre vessel 2 moles of cyclohexane are mixed with 2 moles of hex-1-ene then 

EASY
IMPORTANT

Initial pressure of AB3(g)  is 800 mm and total pressure at equilibrium is 900 mm of Hg. Calculate the percentage of AB3 dissociated in the following reaction:

AB3(g)AB2(g)+12B2(g)