Given
`C_(("graphite"))+O_(2)(g)toCO_(2)(g)`,
`Delta_(r)H^(@)=-393.5kJmol^(-1)`
`H_(2)(g)+1/2O_(2)(g)toH_(2)O(l)`,
`Delta_(r)H^(@)=-285.8kJmol^(-1)`
`CO_(2)(g)+2H_(2)O(l)toCH_(4)(g)+2O_(2)(g)`,
`Delta_(r)H^(@)=+890.3kJmol^(-1)`
Based on the above thermochemical equations, the value of `Delta_(r)H^(@)` at 298 K for the reaction
`C_(("graphite"))+2H_(2)(g)toCH_(4)(g)` will be :

Options

A. `+144.0kJmol^(-1)`
B. `-74.8kJmol^(-1)`
C. `-144.0kJmol^(-1)`
D. `+74.0kJmol^(-1)`

Answer

A