Question

N2O4(g) 2NO2(g), Kc = 4. This reversible reaction is studied graphically as shown in figure. Select the correct statements out of I, II and III.

I : Reaction quotient has maximum value at point A

II : Reaction proceeds left to right at a point when

[N2O4] = [NO2] = 0.1 M

III: Kc = Q when point D or F is reached :

• A. I, II
• B. II,III
• C. I, III
• D. I, II, III

Answer 1

Answer: (B)

II,III

Answer 2

(I) N2O4 2NO2 Kc = 4

at point — A

$Q = \frac{\left\lbrack \Pr oduct \right\rbrack}{\left\lbrack {Re}ac\tan t \right\rbrack} = 0$

So, Q have minimum value at point A.

(II) at point [N2O4] = [NO2] = 0.1 M

$Q = \frac{\left\lbrack NO_{2} \right\rbrack^{2}}{\left\lbrack N_{2}O_{4} \right\rbrack} = \frac{0.1 \times 0.1}{0.1} = 0.1$

Q < Kc

So, reaction proceeds left to right

(III) Kc = Q at point [D & F].) N2O4 2NO2

Kc = 4

at point — A