Chemistry Dout

[joel]

Explain why the standard enthalpy change of formation for water is identical to the standard enthalpy change of combustion of hydrogen.

Taken from 9701/02/O/N/03 Question 3 (a) (iii)

[The SMA]

Standard enthalphy change of formation of water and Standard enthalphy change of combustion of Hydrogen are the same because Hydrogen reacts with oxygen to form water.

Standard enthalphy change of formation of water:
H2 (g)  + 1/2 O2 (g) --> H2O (l)   -286kj/mol

Standard enthalphy change of combustion of Hydrogen:
H2 (g) + 1/2 O2 (g) --> H2O (l)    -286kj/mol