Calculate K.?

Question

consider the reaction: 2NO2 + Cl2 ----> 2NOCl
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The initial pressure of NO2 was 1.577atm and the initial pressure of Cl2 was 0.427atm. At equilibrium, the partial pressure of NOCl is 0.624atm. Calculate K.

Answer 1

For: aA + bB = cC + dD, K may be defined as;

K = (P(C)^c * P(D)^d) / (P(A)^a * P(B)^b), i.e., the pressures of the reactants over the products, with the pressures raised to the coefficients of the reactants.

For this reaction:
a = 2
A = 1.577 atm
b = 1
B = .427 atm
c = 2
C = .624 atm
d and D are ignored.

K = (.684)^2 / (1.577^2 * .427)
K = 0.389376 / (2.486929 * .427)
K = 0.389376 / 1.061918683
K = 0.367 (solution!)