Applications of Equilibrium Constant

IMPORTANT

Applications of Equilibrium Constant: Overview

This topic covers concepts, such as, Degree of Dissociation for Equilibrium Reactions, Applications of Equilibrium Constants, Predicting Direction of Reaction, Predicting Extent of Reaction & Calculating Composition of Equilibrium Mixture etc.

Important Questions on Applications of Equilibrium Constant

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 :

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

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?

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

Value of Kp for the reaction SO2g+NO2gSO3g+NOg  is 25 at cartain temperature and 4atm pressure.
Initially if we take 2 moles of each of the four gases and 2 moles of inert gas, what would be the equilibrium partial pressure of SO2 ? 

HARD
IMPORTANT

Consider the following reaction equilibrium:

N2g+3H2(g)2NH3(g)

Initially in 2 L flask 1 mole of N2 and 3 mole of H2 are kept. If equilibrium state the number of moles of N2 is 0.6, then the total number of moles of all gases present in the flask is

HARD
IMPORTANT

PCl5gPCl3 g+Cl2 g

The degree of dissociation of PCl5 at one atmosphere is 0.3. The pressure at which PCl5 is dissociated to 50% is nearly:

HARD
IMPORTANT

PCl5gPCl3g+Cl2g

α is the degree of dissociation, P1T1P2 and T2 are the initial pressure, initial temperature, equilibrium pressure and temperature, respectively. What is the value of α constant V?

HARD
IMPORTANT

Consider the following equilibrium in a closed container PCl5(g)PCl3(g)+Cl2(g)  PCl5. Gas at a certain pressure is introduced in the container at 27°C. However, the total pressure at equilibrium at 207°C was found to be double the initial value. The % dissociation of PCl5 at 207°C is:

MEDIUM
IMPORTANT

For the reaction N2O4(g)2NO2(g), the correct relationship between degree of dissociation α and equilibrium constant Kp is:

(P=equilibrium total pressure)

HARD
IMPORTANT

A vessel contains H2 and H2S gases at partial pressures of 1 and 2 atm, respectively, at a certain temperature the reaction, 8H2S(g)  8H2(g)+S8(s) occurs. It is found that [nH2nH2S]at  equilibrium=[nH2SnH2] at time, t=0  (n represents no. of moles). Identify the correct value of the given property.

HARD
IMPORTANT

At a certain temperature, 2 moles of CO and 3 moles of Cl2 were mixed and allowed to reach equilibrium in a 5.0 L vessel according to the reaction CO(g) + Cl2(g) COCl2 (g).

At equilibrium, if 1 mole of CO is present, then equilibrium constant (Kc) for the reaction is:

HARD
IMPORTANT

MgSO47H2O(S)MgSO4.5H2O(S)+2H2O(g)

The above equilibrium is reached in a closed contained initially having dry inert gases. At equilibrium relative humidity of the mixture is 0.4. What is Kp if aqueous tension at the same temperature is 50 mm Hg ?

MEDIUM
IMPORTANT

A2B5 (gas) decomposes in presence of Helium with total initial pressure of 100 mm of Hg in a closed flask. After 50% of A2B5 decomposed equilibrium is reached with a net pressure of 140 mm of Hg. What is Kp for A2B5(g)A2B(g)+2B2(g)

MEDIUM
IMPORTANT

Equilibrium A4(g)4Ag  is established in a close container. A very tiny pinhole is made and very-very little amount of equilibrium mixture (equilibrium not altered) is effused out, in which mass percentage of atomic A is 40%. Hence degree of dissociation of A4 is -