Chlorine gas, Cl2(g), reacts with nitric oxide, NO(g), to form nitrosyl chloride, NOCl(g), via the reaction Cl2(g)+2NO(g)⇌2NOCl(g)
The thermodynamic data for the reactants and products in the reaction are given in the following table:
Substance ΔfG∘(kJ mol−1)
Cl2(g). 0

NO(g) 86.71

NOCl(g) 66.30
The diagram below serves as a pictorial depiction of the relationship between the Gibbs energy change of a reaction under nonstandard conditions and the standard Gibbs energy change in the equation ΔrG=ΔrG∘+RTlnQ. Point A is at standard conditions, which means all reagents have a partial pressure of 1 bar, as shown in the equation below point A. Points B and C are at nonstandard conditions. Point X indicates the point at which equilibrium lies. The axis labeled Q refers to the reaction quotient. The actual value of Q at the point of equilibrium is K, which is the equilibrium constant at 298 K. Using standard Gibbs energy of formation values given in the introduction, calculate the equilibrium constant K of the reaction

Cl2(g)+2NO(g)⇌2NOCl(g)

The standard Gibbs energy change of the reaction represents the drive the reaction has under standard conditions to move toward equilibrium from point A to point X in the diagram.

Express the equilibrium constant numerically using three significant figures.