The equilibrium constant is given for one of the reactions below. determine the value of the missing equilibrium constant.

h2(g) + br2(g) ⇌ 2 hbr(g) kc = 3.8 × 104
4 hbr(g) ⇌ 2 h2(g) + 2 br2(g) kc = ?

To calculate Kc of the second step, we must observe the first reaction.
If we rotate the first reaction and multiplay it by 2 we get the same thing.

So the rotation means 1/kc(first reaction)
And by multiplying it by 2, K should be squared.

Kc2=1/(kc1)^2=6.92*10^-10

North atlantic current or north atlantic drift is the answer