Enthalpy ($H$) is equal to

The internal energy change (in $\mathrm{J}$) when $90 \mathrm{g}$ of water undergoes complete evaporation at $100°\mathrm{C}$ is ..............

(Given : ${\mathrm{\Delta H}}_{\mathrm{vap}}$ for water at $373 \mathrm{K}=41 \mathrm{kJ}/\mathrm{mol}$, $\mathrm{R}=8.314 {\mathrm{JK}}^{-1} {\mathrm{mol}}^{-1}$)

For which of the following systems, the difference between $\mathrm{\Delta H}$ and $\mathrm{\Delta U}$ is not significant?

(i) Solids

(ii) Gases

(iii) Mixture of gases and liquids

(iv) Liquids

The combination of plots which does not represent isothermal expansion of an ideal gas is

$\left(\mathrm{A}\right)$

$\left(\mathrm{B}\right)$

$\left(\mathrm{C}\right)$

$\left(\mathrm{D}\right)$

$\mathrm{A}$ fish swimming in water body when taken out from the water body is covered with a film of water of weight $36 \mathrm{g}$. When it is subjected to cooking at $100 °\mathrm{C}$, then the internal energy for vaporization in ${\mathrm{kJmol}}^{-1}$ is integer]

[Assume steam to be an ideal gas. Given ${\mathrm{\Delta }}_{\mathrm{vap}}{\mathrm{H}}^{\ominus }$ for water at $373 \mathrm{K}$ and $1$ bar is $41.1 \mathrm{kJ}{ \mathrm{mol}}^{-1}:\mathrm{R}=8.31 \mathrm{J}{ \mathrm{K}}^{-1}{ \mathrm{mol}}^{-1}$]

Under the isothermal condition, a gas at $300\mathrm{ }\mathrm{K}$ expands from $0.1\mathrm{ }\mathrm{L}$ to $0.25\mathrm{ }\mathrm{L}$ against a constant external pressure of $2$ bar. The work done by the gas is

(Given that $1\mathrm{ }\mathrm{L}$ bar$=100\mathrm{ }\mathrm{J}$)