Question

14-1)Consider the reaction of 2NO_2(g)↔N₂O_4(g) if the K_p for the reaction is known to be 0.480 at 25°C, does the reaction favor product or reactant at this temperature?

14-2) For the reaction shown, Kc= 5.88 X 10^-32

Ag₂S_(s) +2H⁺_(aq)çè2Ag⁺_(aq) + H₂S_(aq)

If we start with 2M AgNO₃, and .1M H₂S, 2M HNO₃ , and 25.g of Ag₂S in which direction will it proceed?

14-3) The reaction H₃PO_4(aq) + 3OH^-_(aq) ↔ 3H₂O_(l) + PO_4(aq)^3- is exothermic. What will happen if:

a) the system is cooled?

b) PO_4(aq)^3- is removed?

c) HCl is added?

d) The pressure is decreased?

e) a catalyst is added?

Answer 1

(14)(1) 2NO_2(g)↔N₂O_4(g)   

Given K_p = 0.480

We know that G = -RTln K_p

Where R = gas constant = +ve    

           T = temperature = 25oC = 298 K = +ve

So G = -RTln K_p

            = -(8.314 (298) x ln 0.480

            = +1.18x10³ J

            = +1.18 kJ

Since G is +ve the reaction is non-spontaneous So the reaction favours in reactant side.