`723` KJ mol`""^(-1)` heat is released when 1 molemethanol combustions in present of `O_(2)`. What amount of heat is enlisted of one mole of `O_(2)` is used?

Options

A. 241 kJ
B. 723 kJ
C. 482 kJ
D. 924 KJ

Answer

C

Explanation

Combusion reaction of methanol,
`CH_(3) OH_((l)) + (3)/(2) O_(2(g)) = CO_(2(g)) + 2H_(2) O_((l)) , Delta H= -723` kJ
1 mole `(3)/(2)` mole
therefore `(3)/(2)` moles `O_2` is used in this reaction.
If 1 mole `O_2` is used.
then free energy `= (2)/(3) xx` combustion energy 723
`= 482` kJ