Question

For questions 11, 12, and 13, consider the particle representation of a reaction below. Boxes I-IV represent 1.00 L volumes, and each particle shown represents one mole of each component. At 25°C, Kc 9, and AH -338 kJ. IV I. П. Ш. OO

Why is the answer B?

Answer 1

Let the reaction be:

2 A2 + B2 -> 2 A2B

I)

Q = [A2B]^2 / [A2]^2[B2]

= 3^2 / (1^2 * 1)

= 9

Qc is equal to Kc.

So, reaction will not shift

II)

Q = [A2B]^2 / [A2]^2[B2]

= 1^2 / (3^2 * 3)

= 1/27

Qc is less than Kc.

So, reaction will shift to the right

III)

Q = [A2B]^2 / [A2]^2[B2]

= 4^2 / (1^2 * 2)

= 8

Qc is less than Kc.

So, reaction will shift to the right

IV)

Q = [A2B]^2 / [A2]^2[B2]

= 4^2 / (1^2 * 1)

= 16

Qc is greater than Kc.

So, reaction will shift to the left

Answer: B