The equilibrium constant for reaction 1 is K.....?

how do i figure out problems like this?
do i check which ones cancel out?

The equilibrium constant for reaction 1 is K. The equilibrium constant for reaction 2 is ___?

(1) SO2 (g) + (1/2) O2 (g) (right and left arrows)SO3 (g)
(2) 2SO2 (g) + O2 (g) (right and left arrows) 2SO3 (g)

A) K2 B) 2K C) -K2 D) 1/K2 E) 1/2K

how do i know what k is?

1 answer

You don't know what K is but you don't need to know. Equation 2 is the same as equation 1 but multiplied by 2. So the K for equation 2 is K for equation 1 squared; i.e., K12