$A$ 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 ....... $J$.

If for a given substance the melting point is $T_B$ and the freezing point is $T_A$,then which graph correctly shows the variation of entropy change $(\Delta S)$ with temperature $(T)$?

If $100$ mole of $H_2O_2$ decomposes at $1$ bar and $300$ $K$,the work done $(kJ)$ by $50$ mole of $O_{2(g)}$ as it expands against $1$ bar pressure is............. $kJ$
$2H_2O_{2(l)} \rightleftharpoons 2H_2O_{(l)} + O_{2(g)}$
$(R = 8.3 \ J \ K^{-1} \ mol^{-1})$

An ideal gas in a thermally insulated vessel at internal pressure $= P_1$,volume $= V_1$ and absolute temperature $= T_1$ expands irreversibly against zero external pressure,as shown in the diagram. The final internal pressure,volume and absolute temperature of the gas are $P_2, V_2$ and $T_2$,respectively. For this expansion,
$(A) \ q = 0$
$(B) \ T_2 = T_1$
$(C) \ P_2 V_2 = P_1 V_1$
$(D) \ P_2 V_2^\gamma = P_1 V_1^\gamma$

In the reaction at $300 \ K$:
$C_6H_6(\ell) + \frac{15}{2}O_{2(g)} \to 6CO_{2(g)} + 3H_2O(\ell) \quad \Delta H = -3271 \ kJ$
What is the value of $\Delta U$ for the combustion of $1.5 \ mol$ of benzene at $27 \ ^oC$? $..... \ kJ$

Enthalpy of neutralisation of acetic acid by $NaOH$ is $-50.6 \ kJ/mol$ and the heat of neutralisation of a strong acid with a strong base is $-55.9 \ kJ/mol$. What is the value of $\Delta H$ for the ionisation of $CH_3COOH$ in $kJ/mol$?