Question

When 1 mole of methane is burned at constant pressure, 890kJ of energy is released as heat. Calculate change H for a process in which a 5.8g sample of methane is burned at constant pressure (show and explain how this is calculated)

Answer 1

CH4 + 2 O2 -----------------> CO2 + 2 H2O

16 g       64 g                                                   heat energy = 890kJ

16 g of CH4   ------------------   delta H = 890 kJ

5.8 g of CH4 ------------------- ??

change in H = 5.8 x 890 / 16

                   = 322.6 kJ

change in H    = 322.6 kJ