Thermochemistry

 

 34) CH3OH(g) CO(g) + 2H2(g)          ΔH = +90.7 kJ

 

       (a) Heat is absorbed because a positive sign for an enthalpy change, ΔH, represents an endothermic reaction.

                

       (b) m = 1.60 kg CH3OH

            ΔH = 1.60 kg CH3OH x 103 g/kg x 1 mol CH3OH/32.05 g CH3OH x 90.7 kJ/1 mol CH3OH = 4.53 x 103 kJ

 

       (c) ΔH = 64.7 kJ

            m = 64.7 kJ x 1 mol CH3OH/90.7 kJ x 2 mol H2/1 mol CH3OH x 2.02 g H2/1 mol H2 = 2.88 g H2

 

       (d) ΔH = -90.7 kJ

 

       (e) m = 32.0 g CO

            ΔH = 32.0 g CO x 1 mol CO/28.01 g CO x -90.7 kJ/1 mol CO = -104 kJ