Question

When $10$ g of methane is burnt in oxygen, the heat evolved is $560$ kJ. What is the heat of combustion (in ${\text{kJ mol}}^{-1})$ of methane?

• A. $-1120$
• B. $-968$
• C. $-896$
• D. $-560$

Answer 1

The correct option is C $-896$

It is given that when $10$ g of methane is burnt in oxygen, the heat evolved is $560$ kJ.

Number of moles of methane $=\frac{10}{16}=0.625mol$

For $10$ g of methane, the heat evolved is $560$ kJ and so, for $16$ g of methane, the heat evolved will be $=\frac{560}{10}\times 16=896$ $kJ$

Hence, the heat of combustion of methane is $896$ kJ/mol.

Option C is correct.