In an experiment, a spirit burner is used to heat 250 cm³ of water by burning methanol (CH₃OH). (A_r values: C = 12.0, H = 1.0, O = 16.0; specific heat capacity of water = 4.18 J g^–1°C^–1)
Results:
Starting temperature of water = 20.0°C
Starting mass of burner + fuel = 248.8 g
Final temperature of water = 43.0°C
Final mass of burner + fuel = 245.9g

a. How many joules of heat energy went into the water?

b. How many moles of fuel were burnt?

c. Calculate an experimental value for the enthalpy change of combustion of methanol from these results.

d. Suggest three reasons why your answer is much smaller than the accepted standard enthalpy of combustion of methanol.