Hydrogen gas and fluorine gas react to form hydrogen fluoride gas: H2 (g) + F2 (g) = 2 HF (g) If an equilibrium mixture at 25°C contains 0.425 M H2 and 0.110 M F2, what is the concentration of HF in the mixture? The equilibrium constant at 25°C is 2.3 x 102. Hydrogen chloride decomposes to hydrogen gas and chlorine gas 2 HCl (g) = H2(g) + Cl2 (g) The equilibrium constant, Kc, for this reaction is 54.3. If 0.50 mol HCl is placed in a 2.0 flask, what is the composition of hydrogen chloride (HCl) in molarity? Using the information from the previous problem: Hydrogen chloride decomposes to hydrogen gas and chlorine gas 2 HCl (g) = H2(g) + Cl2 (g) The equilibrium constant, Kc, for this reaction is 54.3. If 0.50 mol HCl is placed in a 2.0 flask, what is the composition of hydrogen gas in molarity?