Question

The heat of combustion of carbon is –94 kcalat 1 atmpressure. The intrinsic energy of $CO_{2}$ is

• A.
  • 94 kcal
• B. –94 kcal
• C.
  • 47 kcal
• D. –47 kcal

Answer 1

Answer: (B)

–94 kcal

Answer 2

$C_{(s)} + O_{2(g)} \rightarrow CO_{2}(g);\Delta H = - 94kcal$

$\mathbf{\Delta H = \Delta E + \Delta}\mathbf{n}_{\mathbf{g}}\mathbf{RT}$; $\mathbf{\Delta}\mathbf{E = ?}$

$\Delta n_{g} = 1 - 1 = 0$; $\Delta H = \Delta E$; $\Delta E = - 94kcal$