For the reaction $2A_{(g)} + B_{(g)} \to 2D_{(g)}$,given $\Delta U^{\theta} = -10.5 \ kJ$ and $\Delta S^{\theta} = -44.1 \ J \ K^{-1}$. Calculate $\Delta G^{\theta}$ for the reaction at $298 \ K$ and predict whether the reaction may occur spontaneously.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) For the reaction $2A_{(g)} + B_{(g)} \to 2D_{(g)}$,the change in the number of gaseous moles is $\Delta n_{g} = 2 - (2 + 1) = -1 \ mol$.
First,calculate $\Delta H^{\theta}$ using the relation $\Delta H^{\theta} = \Delta U^{\theta} + \Delta n_{g} R T$:
$\Delta H^{\theta} = -10.5 \ kJ + (-1 \ mol)(8.314 \times 10^{-3} \ kJ \ K^{-1} \ mol^{-1})(298 \ K)$
$\Delta H^{\theta} = -10.5 \ kJ - 2.477 \ kJ = -12.977 \ kJ$.
Now,calculate $\Delta G^{\theta}$ using $\Delta G^{\theta} = \Delta H^{\theta} - T \Delta S^{\theta}$:
$\Delta G^{\theta} = -12.977 \ kJ - (298 \ K)(-44.1 \times 10^{-3} \ kJ \ K^{-1})$
$\Delta G^{\theta} = -12.977 \ kJ + 13.142 \ kJ = +0.165 \ kJ$.
Since $\Delta G^{\theta} > 0$,the reaction is non-spontaneous at $298 \ K$.

Explore More

Similar Questions

$A$ mixture of $H_2$ and a sufficient quantity of air at $25\,^{\circ}C$ and $1\ atm$ pressure undergoes complete combustion in a closed rigid adiabatic container,leaving behind $H_2O_{(g)}$ and $N_{2(g)}$. If air is a mixture of $80\% N_2$ and $20\% O_2$ by volume and $C_{P(N_2)}$ and $C_{P(H_2O)g}$ are $7.0$ and $8.0\ cal\ deg^{-1}\ mol^{-1}$ respectively,what will be the maximum temperature attained? (Given that: $(\Delta H^o_f)_{H_2O_{(g)}} = -56.0\ kcal/mol$ and it is independent of temperature)...... $K$

Difficult
View Solution

Enthalpy of sublimation of iodine is $24 \ cal \ g^{-1}$ at $200 \ ^oC$. If specific heat of $I_{2(s)}$ and $I_{2(vap)}$ are $0.055$ and $0.031 \ cal \ g^{-1} K^{-1}$ respectively,then enthalpy of sublimation of iodine at $250 \ ^oC$ in $cal \ g^{-1}$ is

An ideal gas undergoes a reversible isothermal expansion from state $I$ to state $II$ followed by a reversible adiabatic expansion from state $II$ to state $III$. The correct plot$(s)$ representing the changes from state $I$ to state $III$ is(are)
($p$ : pressure,$V$ : volume,$T$ : temperature,$H$ : enthalpy,$S$ : entropy)

Enthalpy of fusion and enthalpy of vaporization for water respectively are $6.01 \ kJ \ mol^{-1}$ and $45.07 \ kJ \ mol^{-1}$ at $0^{\circ}C$. What is enthalpy of sublimation at $0^{\circ}C$?

For the reaction $2C_6H_6(l) + 15O_2(g) \rightarrow 12CO_2(g) + 6H_2O(l)$ at $25 \ ^\circ C$,calculate the difference between the heat of reaction at constant volume and constant pressure in $kJ$.

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo