The enthalpy of combustion of one mole of benzene, carbon and hydrogen

Explanation

(i)`C_(6)H_(6(l))+15/2O_(2)to6CO_(2(y))+3H_(2)O_((l))DeltaH=-3267` kJ/mol
(ii) `C_((s))+O_(2(s))toCO_(2(s))DeltaH=-393.5`kJ/mol
(iii) `H_(2(g))+1/2O_(2(g))toH_(2)O_((l))DeltaH=-285.8` kJ/mol
`6C_((s))+3H_(2(s))toC_(6)H_(6)DeltaH=?` Required Eqn
`X^(ly)eq(ii)by 6" " 6C_((s))+cancel(6O)_(2(g))tocancel(6CO)_(2(g))Deltah=-2361`
`X^(ly)eq(ii) by 3 " " 3H_(2(g))+cancel(3/2O)_(2(g))tocancel(3H_(2)O)_((l))DeltaH=-857.4`
Reverse eqn (i)`cancel(6O)_(2(g))+cancel(3H_(2)O)_((l))toC_(6)H_(6(l))+cancel(15/2O_(2)) DeltaH=3267`
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`6C_((s))+3H_(2(g))toC_(6)H_(6)DeltaH=48.6kJ//"mol"`