Question

Assertion : For the combustion of methane, $\Delta E>\Delta H$
Reason : $\Delta H$ is related by $\Delta E$ by the expression. $\Delta H=\Delta E+\Delta n R T$

• A. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
• B. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
• C. If Assertion is true but Reason is false.
• D. If both Assertion and Reason are false.

Answer 1

Answer: (A)

Combustion of methane is
$CH _{4}+2 O _{2} \longrightarrow CO _{2}+2 H _{2} O$
The relation in between $\Delta H$ and $\Delta E$ is
$\Delta H=\Delta F+\Delta n R T$
$\Delta n =n_{p}-n_{r}=1-3=-2$
$\Delta H =\Delta E-2 T$
So, $\Delta H <\Delta E$
Hence, reason is correct explanation of assertion.