$9.0 \ g$ of $H_2O$ is vaporised at $100 \ ^oC$ and $1 \ atm$ pressure. If the latent heat of vaporisation of water is $x \ J/g$,then $\Delta S$ is given by

Find the heat required to convert $10 \ g$ of ice at $0.0^{\circ} C$ into water at $30^{\circ} C$. (Enthalpy of fusion of ice $= 333.5 \ J \ g^{-1}$, $C_p$ of water $= 4.18 \ J \ g^{-1} \ K^{-1}$) (in $kJ$)

The enthalpy of formation of $H_2O$ is $-68 \ k.cal/mol$. Calculate the enthalpy of formation of $OH^-$. Given that the enthalpy of neutralization of $H^+$ and $OH^-$ is $-13.7 \ k.cal/mol$.

For the reaction $2H_{(g)} \to H_{2(g)}$,the signs of $\Delta H$ and $\Delta S$ are:

$A$ gas present in a cylinder expands against a constant pressure of $1 \, atm$ from a volume of $2 \, L$ to a volume of $6 \, L$. In doing so,it absorbs $800 \, J$ of heat from the surroundings. The change in internal energy of the process is ....... $J$.

What is the difference between $\Delta H$ and $\Delta U$ for the combustion of methane at $25\,^oC$?