PLEASE HELP EMERGENCY

Question

24.The equilibrium constant for the reaction: 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) is

 Kc = 1.7 × 10⁶.  What is the equilibrium constant for the reaction, 2SO₃(g) ⇌ O₂(g) + 2SO₂(g) ?

          

 a) 1.7 x 10^-6            b) 5.9 x 10^-7              c) 1.7 x 10⁶              d) 5.9 x 10⁷

25. Experimental data is given below for the reaction A+ B → C. What is the

            Rate law for the reaction? 

[A](M)	[B](M)	Initial rate (M/s)
0.100	0.100	1.26 x 10-3
0.200	0.100	2.52 x 10-3
0.100	0.200	5.04 x 10-3

        a) rate = k [A] [B]                                                  b) rate = k [A] [B]²      

        c) rate = k [A]² [B]                                                d) rate = k [A]²                       

Answer 1

24 The reaction is the reverse of the given one, so the K for the reaction = 1/K for the original reaction.

1/1.7 x 10⁶ = 5.9 x 10^-7.

25

First compare R₂/R₁:

(2.52 x 10^-3)/(1.26 x 10^-3) = [0.200]^x / [0.100]^x

2 = 2^x thus x = 1 so R α [ A ]¹

Next, compare R₃/R₁:

(5.04 x 10^-3)/(1.26 x 10^-3) = [0.200]^y / [0.100]^y

4 = 2^y thus y = 2 so R α [B]²

Thus, the rate law is: Rate = k [A] [B]² which is choice (b)