(a(i))[2]
Explain, in terms of bond breaking and bond making, why this reaction takes in energy.
(a(ii))[1]
The transfer of thermal energy in a chemical reaction is known as the enthalpy change. Write the symbol for enthalpy change, and show the sign for an endothermic enthalpy change.
(b(i))[1]
Name one additional substance produced when carbon-containing fuels burn incompletely.
(b(ii))[1]
State one harmful effect of carbon monoxide.
(c)[2]
Describe two advantages of a hydrogen-oxygen fuel cell compared with a gasoline/petrol engine.