The enthalpy of dilution of $4 \ M \ HCl$ to $2 \ M \ HCl$ is $-2.5 \ kJ/mol$. Find the enthalpy change when $500 \ mL$ of $4 \ M \ HCl$ is diluted to $2 \ M \ HCl$ (in $kJ$).

What is the enthalpy of vaporization of ethanol in $kJ/mol$? Given: boiling point $(b.p.)$ = $79.5 \, ^\circ C$ and entropy change $(\Delta S_{vap})$ = $109.8 \, J K^{-1} mol^{-1}$.

For the reaction $X_2O_{4(g)} \to 2XO_{2(g)}$,given $\Delta U = 2.1 \, kcal$ and $\Delta S = 20 \, cal \, K^{-1}$ at $300 \, K$. Calculate $\Delta G$ in $kcal$.

$500 \ J$ of energy is transferred as heat to $0.5 \ mol$ of Argon gas at $298 \ K$ and $1.00 \ atm$. The final temperature and the change in internal energy respectively are $:$ Given $: R = 8.3 \ J \ K^{-1} \ mol^{-1}$

Which of the following is true for the reaction $H_2O_{(l)} \rightleftharpoons H_2O_{(g)}$ at $100 ^oC$ and $1 \text{atm}$ pressure?

At $298 \ K$,$\Delta_r U^{\ominus}$ and $\Delta_r S^{\ominus}$ for the following reaction are $-10.5 \ kJ$ and $+44.1 \ J \ K^{-1} \ mol^{-1}$ respectively. The reaction is: $2 \ X_{(g)} + Y_{(g)} \longrightarrow 2 \ Z_{(g)}$. What is $\Delta_r G^{\ominus}$ (in $kJ$) for this reaction? $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$