Question 1

Le-Chateliers' principle is not applicable to

Accepted Answer

Le-Chatelier principle is not applicable to pure solids and liquids because they experience negligible change in concentration during chemical equilibrium.

Question 2

The ratio K_P K_C for the reaction CO _ ( g ) + 1 2 O _ 2( ~g ) CO _ 2( ~g ) is:

Accepted Answer

CO ( g )+ 1 2 O _2( ~g ) CO _2( ~g ) K _ P and K _ C are related as K _ P = K _ C ( RT )^ n _ g n _ g = n _ P - n _ R =1-1 1 2 =- 1 2 n _ g for the given reaction =- 1 2 K _ P K _ C = 1 RT

Question 3

For an isomerisation reaction A B, the temperature dependence of equilibrium constant is given by _e K=4.0- 2000 T The value of S^ at Hook is, therefore

Accepted Answer

van't Hoff equation giving variation of equilibrium constant, K with temperature T is _e K=- H^ R T + S^ R Given, _e K=- 2000 T +4.0 S^ / R=4 S^ =4 R

Question 4

PCl _ 5 is dissociating 50 \% at 250^ C at a total pressure of P atm. If equilibrium constant is K _ p , then which of the following relation is numerically correct -

Accepted Answer

K _ p = P 3 P 3 P 3 = P 3

Question 5

The ratio K_ p K_ c for the reaction CO (g)+ 1 2 O _ 2 (g) CO _ 2 (g) is:

Accepted Answer

K_ P =K_ C (R T)^ n_ g For the reaction CO ( g )+ 1 2 O _ 2 (g) CO _ 2 ( ~g ) n_ g =1- (1+ 1 2 )=- 1 2 K _ P = K _ C RT ; K _ P K _ C = 1 RT

Chemical Equilibrium — Previous Year Questions & Solutions