The equilibrium constant is given for one of the reactions b

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 × 10^4

2 HBr(g) H2(g) + Br2(g) Kc = ?

A) 1.9 × 10^4

B) 5.3 × 10^-5

C) 2.6 × 10^-5

D) 6.4 × 10^-4

E) 1.6 × 10^3

please explain everything

Solution

H2_(g) + Br2_(g) <----------> 2HBr_(g) Kc = 3.8 x 10⁴  

if we reverse the reaction

2HBr_(g) <----------> H2_(g) + Br2_(g) Kc¹ = 1/Kc

Kc¹ = 1/ 3.8 x 10⁴

Kc¹ = 2.6 x 10^-5

answer = option C = 2.6 x 10^-5