Question

Figure out what is wrong with each questions and answers:

1.) For the reaction 2A(g)+3B(g)⇌C(g)

Kc = 78.0 at a temperature of 239 ^∘C .Calculate the value of Kp.

Ans: K_p=2.50 x 10^-5

2.) For the reaction X(g)+2Y(g)⇌3Z(g)

Kp = 1.38×10⁻² at a temperature of 81 ^∘C .Calculate the value of Kc.

Ans: K_c = 1.38 x 10^-2

3.) For the reaction 2CH4(g)⇌C2H2(g)+3H2(g)

K = 0.145 at 1590 ^∘C . What is Kp for the reaction at this temperature?

Ans: K_p = 3390

4.) For the reaction N2(g)+3H2(g)⇌2NH3(g)

Kp = 2.75×10⁻³ at 255 ^∘C . What is K for the reaction at this temperature?

Ans: K= 5.17

PLEASE HELP AND THANK YOU SO MUCH!!!

Answer 1

1) we know that

Kp = Kc (RT)^dn

where

dn = moles of gases in products - moles of gases in reactants

given

2A + 3B ---> C

so

dn = 1 - 2 - 3 = -4

Kc = 78

T = 239 C

T = 239 + 273

T = 512 K

so

Kp = 78 x ( 0.0821 x 512)^-4

Kp = 2.5 x 10-5

2)

given

X + 2Y ---> 3 Z

dn = 3 - 2 - 1

dn = 0

so

Kp = Kc (RT)^0

Kp = Kc

so

Kc = 1.38 x 10-2

3)

given

2 CH4 --> C2H2 + 3H2

dn = 1 + 3 - 2 = 2

T = 1590 C = 1863 K

so

Kp = 0.145 x ( 0.0821 x 1863)^2

Kp = 3392

4) given

N2 + 3H2 --> 2NH3

so

dn = 2 - 3 - 1 = -2

T = 255 + 273 = 528 K

2.75 x 10-3 = Kc x ( 0.0821 x 528)^-2

Kc = 5.13

so

the value of Kc is 5.13