25℃ 152.0 kPa N2O4(g) 101.3 kPa NO2(g) 51.9 kPa

A flask is charged with

152.0 kPa of N2O4(g) and 101.3 kPa NO2(g) at 25℃,

and the following equilibrium is achieved

N2O4(g) ⇌ 2NO2(g)

After equilibrium is reached,

the partial pressure of NO2 is 51.9 kPa.

(a) What is the equilibrium partial pressure of N2O4?

(b) Calculate the value of Kp for the reaction.

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(a) What is the equilibrium partial pressure of N2O4?

ICE 도표를 작성하면,

평형에서, NO2 is 51.9 kPa 이므로,

101.3 + 2x = 51.9

x = (51.9 – 101.3) / 2 = –24.7

152.0 – x = 152.0 – (–24.7)

= 176.7 kPa N2O4(g)

---> equilibrium partial pressure of N2O4

(b) Calculate the value of Kp for the reaction.

Kp = (P_NO2)^2 / (P_N2O4)

( 참고: 평형상수식 https://ywpop.tistory.com/7136 )

= (51.9)^2 / (176.7)

= 15.24

(c) Calculate Kc for the reaction.

Kc = Kp / (RT)^Δn

( 참고 https://ywpop.tistory.com/6523 )

Δn = 기체 생성물들의 몰수 – 기체 반응물들의 몰수

= 2 – 1 = 1

Kc = Kp / (RT)^Δn

= 15.24 / [0.08206 × (273.15 + 25)]

= 0.6229

[키워드] N2O4(g) ⇌ 2NO2(g) 평형 기준, kc kp 기준, kp kc 기준