If the heat of combustion of isobutane at constant volume is $Q_v$,what will be the heat of combustion of one mole of isobutane at constant pressure and standard conditions? (Given: $\Delta n_g = -3.5$)

In the complete combustion of butanol $C_4H_9OH_{(l)}$,if $\Delta H$ is the enthalpy of combustion and $\Delta E$ is the heat of combustion at constant volume,then

One mole of an ideal gas is allowed to expand reversibly and adiabatically from a temperature of $27\, ^{\circ}C$. If the work done during the process is $3\, kJ$,then the final temperature of the gas is $(C_v = 20\, J\, K^{-1}\, mol^{-1})$ .....$K$

$A$ gas expands isothermally from $10 \, dm^3$ to $20 \, dm^3$ at a constant external pressure of $1 \, atm$. If it absorbs $800 \, J$ of heat from the surroundings,what is the value of $\Delta U$ in $J$ for this process?

$1 \, \text{mole}$ of an ideal gas is allowed to expand reversibly and adiabatically from a temperature of $27^{\circ}C$. The work done is $3 \, \text{kJ} \, \text{mol}^{-1}$. The final temperature of the gas is $...... \text{K}$ (Nearest integer). Given $C_{V} = 20 \, \text{J} \, \text{mol}^{-1} \, \text{K}^{-1}$.

Which of the following is not equal to zero in a cyclic process?