partial preesure of hydrogen peroxide calculation from (equilibrium constant) Kc

Question 1 –Consider the following equilibrium reaction at 160.00 ∘C. H2(𝑔) + O2(𝑔) ⇌ H2O2(𝑔) (𝐾𝐶 = 7.109 note: this is NOT 𝐾𝑝) a) If 0.420 atm of H2O2(𝑔) is initially present, calculate the equilibrium partial pressures in atm of H2(𝑔), O2(𝑔) and H2O2(𝑔) b) Once the system has established equilibrium, the volume is doubled. Would the partial pressure of H2O2(𝑔) increase, decrease, or not change in order to establish a new equilibrium?