Question

For complete combustion of ethanol,
$C_2{H}_{5}OH\left(l\right)+3O_2\left(g\right)\to 2C{O}_2\left(g\right)+3H_{2}O\left(l\right),$
the amount of heat produced as measured in bomb calorimeter, is 1364.47 kJ $mo{l}^{-1}at{25}^{o}C.$ Assuming ideality the enthalpy of combustion, ${△}_{C}H,$ for the reaction will be:
(R = 8.314 kJ mol^{-1})

• A. -1460.50 kJ $mo{l}^{-1}$
• B. -1350.50 kJ $mo{l}^{-1}$
• C. -1366.95 kJ $mo{l}^{-1}$
• D. -1361.95 kJ $mo{l}^{-1}$

Answer 1

The correct option is C -1366.95 kJ $mo{l}^{-1}$

$C_2{H}_{5}OH\left(1\right)+3O_2\left(g\right)\to 2C{O}_2\left(g\right)+3H_{2}O\left(l\right)$
$△U=-1364.47kJ/mole$
$△H=?$
T = 298 K
$△n_g=(2-3=-1)$
$\because △H=△U+△n_{g}RT$
So, $△H$ = -1366.95 kJ/mole