Three moles of an ideal gas are expanded isothermally from a volume of $300 \ cm^3$ to $2.5 \ L$ at $300 \ K$ against a constant external pressure of $1.9 \ atm$. The work done in joules is:

The $\Delta E^o$ of combustion of $2-$methylpropene is $-X \ kJ \ mol^{-1}$. The value of $\Delta H^o$ is

Assertion : $\Delta H$ and $\Delta E$ are almost same for the reaction $N_{2(g)} + O_{2(g)} \rightleftharpoons 2NO_{(g)}$.
Reason : All reactants and products are gases.

Arrange the following isothermal processes in order of the magnitude of the work $(w)$ involved between states $1$ and $2$.
$A$. Expansion in single stage $(w_A)$
$B$. Expansion in multi stages $(w_B)$
$C$. Compression in single stage $(w_C)$
$D$. Compression in multi stages $(w_D)$

Following data is known about the melting of a compound $AB$: $\Delta H = 9.2 \ kJ \ mol^{-1}$,$\Delta S = 0.008 \ kJ \ K^{-1} \ mol^{-1}$. Its melting point is:

Consider the reaction at $300 \ K$:
$C_6H_{6(l)} + \frac{15}{2}O_{2(g)} \longrightarrow 6CO_{2(g)} + 3H_2O_{(l)} ; \Delta H = -3271 \ kJ$
What is $\Delta U$ for the combustion of $1.5 \ mol$ of benzene at $27 \ ^\circ C$? .....$kJ$