The enthalpy of combustion of methane, graphite and dihydrogen at 298 K are, −890.3kJ mol−1–393.5kJ mol−1, and –285.8 kJ mol−1 respectively. Enthalpy of formation of CH4(g) will be
(i) –74.8kJ mol−1
(ii) –52.27kJ mol−1
(iii) +74.8kJ mol−1
(iv) +52.26kJmol−1