Calculating K from Rearranged equations

Question

The equilibrium constant, K_c, for the following reaction is 1.95×10^-2 at 731 K.

2HI(g) H₂(g) + I₂(g)

Calculate K_c at this temperature for the following reaction:

HI(g) 1/2H₂(g) + 1/2I₂(g)

K_c = 

Answer 1

Since the equation of interest is 1/2 the original equation, we simply take the square root of the original K value.

K = √1.95x10^-2

K = 0.140 or 1.40x10^-2