Chemical Equilibrium

24) m_H2 = 1.374 g H₂            V = 2.00 L          R = 0.0821 L·atm/mol·K

      m_Br2 = 70.31 g Br₂          T = 700 K

      (a) m_H2 = 0.566 g H₂

            PV = nRT

            P_H2i = nRT/V = 1.374 g H₂ x 1 mol H₂/2.02 g H₂ x 0.0821 L·atm/mol·K x 700 K/2.00 L = 19.5 atm H₂

            P_Br2i = nRT/V = 70.31 g Br ₂ x 1 mol Br ₂/159.80 g Br ₂ x 0.0821 L·atm/mol·K x 700 K/2.00 L = 12.6 atm Br₂

            P_H2e = nRT/V = 0.566 g H₂ x 1 mol H₂/2.02 g H₂ x 0.0821 L·atm/mol·K x 700 K/2.00 L = 8.05 atm H₂

                              H₂(g)    +    Br₂(g)          2HBr(g)

            P_i(atm)      19.5             12.6                         0

            P_c(atm)     -11.4           -11.4                      +2*11.4

            P_e(atm)      8.05            1.2                          22.8

            P_H2e = 8.05 atm, P_Br2e = 1.2 atm, P_HBre = 22.8 atm

      (b) K_eq = P_HBr²/(P_H2 x P_Br2) = 22.8²/8.05/1.2 = 54