Question

($\Delta$H-$\Delta$U) for the formation of carbon monoxide (CO) from its elements at 298 K is

(R = 8.314 J K–1mol–1)

• A. 1238.78 J mol–1
• B. -2477.57 J mol–1
• C. 2477.57 J mol–1
• D. -1238.78 J mol–1

Answer 1

Answer: (A)

1238.78 J mol–1

Answer 2

$\Delta$H – $\Delta$U = $\Delta$ng RT C(s) + 1/2 O2 (g) $\rightarrow$ CO (g)

$\Delta$ng = 1 –$\frac{1}{2}$ = + $\frac{1}{2}$

$\Delta$H – $\Delta$U = $\frac{1}{2}$× 8.314 × 298 = 1238.78 J mol–1