Calculate the work done in $J$ when $63.50 \ g$ of $Zn$ is dissolved in an open beaker with hydrochloric acid at $300 \ K$. (Atomic mass of $Zn = 63.5 \ amu$)

How much heat in $KJ$ is released during the combustion of $112 \ L$ of water gas at $S.T.P.$? (Water gas is an equimolar mixture of $H_2$ and $CO$)
$H_{2(g)} + \frac{1}{2} O_{2(g)} \rightarrow H_2O_{(g)}; \Delta H = -241.8 \ KJ$
$CO_{(g)} + \frac{1}{2} O_{2(g)} \rightarrow CO_{2(g)}; \Delta H = -283 \ KJ$

The heat of combustion of naphthalene $(C_{10}H_8(s))$ at constant volume is $-5133 \, kJ \, mol^{-1}$. The value of enthalpy change is .... $J$ $(R = 8.314 \, J \, K^{-1} \, mol^{-1}, T = 298 \, K)$.

$C_{(s)} + O_{2(g)} \rightarrow CO_{2(g)} + 400 \; kJ$
$C_{(s)} + \frac{1}{2} O_{2(g)} \rightarrow CO_{(g)} + 100 \; kJ$
When coal of purity $60 \%$ is allowed to burn in the presence of insufficient oxygen,$60 \%$ of carbon is converted into $CO$ and the remaining is converted into $CO_2$.
The heat generated when $0.6 \; kg$ of coal is burnt is (in $; kJ$)

An ideal gas in a thermally insulated vessel at internal pressure $P_1$,volume $V_1$,and absolute temperature $T_1$ expands irreversibly as shown in the following diagram. The final pressure,volume,and absolute temperature of the gas are $P_2$,$V_2$,and $T_2$ respectively. Which is the correct statement for the expansion?

Given the following thermochemical equations:
$(i) S_{(s)} + \frac{3}{2} O_{2(g)} \rightarrow SO_{3(g)} + 2x \, kcal$
$(ii) SO_{2(g)} + \frac{1}{2} O_{2(g)} \rightarrow SO_{3(g)} + y \, kcal$
Find the heat of formation of $SO_{2(g)}$.