Question

$(\Delta H-\Delta U)$ for the formation of carbon monoxide (CO) from its elements at $298\, K$ is $\left(R=8.314\, JK ^{-1} mol ^{-1}\right)$

• A. $-1238.78\, J\, mol ^{-1}$
• B. $1238.78\, J\, mol ^{-1}$
• C. $-2477.57\, J\, mol ^{-1}$
• D. $2477.57\, J\, mol ^{-1}$

Answer 1

Answer: (A)

$C_{(s)}+\frac{1}{2} O _{2(g)} \longrightarrow CO _{(s)}(\Delta H-\Delta U)=-\Delta n R T $
$=-\frac{1}{2} \times 8.314 \times 298=-1238.78$