Chemical Equilibrium

 

24) mH2 = 1.374 g H2            V = 2.00 L          R = 0.0821 L·atm/mol·K

      mBr2 = 70.31 g Br2          T = 700 K

 

      (a) mH2 = 0.566 g H2

 

            PV = nRT

            PH2i = 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

            PBr2i = 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

            PH2e = 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)

            Pi(atm)      19.5             12.6                         0

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

            Pe(atm)      8.05            1.2                          22.8

            

            PH2e = 8.05 atm, PBr2e = 1.2 atm, PHBre = 22.8 atm

 

      (b) Keq = PHBr2/(PH2 x PBr2) = 22.82/8.05/1.2 = 54