List of top Chemistry Questions on Thermochemistry asked in MHT CET

Calculate standard enthalpy change of reaction \[ C_2H_2(g) + \frac{5}{2} O_2(g) \rightarrow 2 CO_2(g) + H_2O(l), \text{ if } \Delta H^\circ(CO_2) = -393 \, \text{kJ mol}^{-1}, \Delta H^\circ(H_2O) = -286 \, \text{kJ mol}^{-1}, \Delta H^\circ(C_2H_2) = 227 \, \text{kJ mol}^{-1} \]

Calculate the standard enthalpy change of following reaction:
$CH_{4(g)} + 2O_{2(g)} \rightarrow CO_{2(g)} + 2H_{2}O_{(l)}$
if $\Delta_{f}H^{\circ}(CH_{4}) = -75~kJ~mol^{-1}$, $\Delta_{f}H^{\circ}(CO_{2}) = -390~kJ~mol^{-1}$, $\Delta_{f}H^{\circ}(H_{2}O) = -286~kJ~mol^{-1}$

Which of the following methods is used to prepare dihydrogen with purity greater than 99.5 % ?

Calculate the enthalpy of vaporisation of ethanol if 11.5 g of ethanol is completely vaporised by supplying 11.8 kJ of heat.

Calculate the standard enthalpy change of the following reaction:
\[ \text{CH}_4{}_{\text{(g)}} + 2\text{O}_2{}_{\text{(g)}} \rightarrow \text{CO}_2{}_{\text{(g)}} + 2\text{H}_2\text{O}_{\text{(l)}} \]
If:
\[ \Delta_f H^\circ (\text{CH}_4) = -75 \, \text{kJ mol}^{-1} \] \[ \Delta_f H^\circ (\text{CO}_2) = -394 \, \text{kJ mol}^{-1} \] \[ \Delta_f H^\circ (\text{H}_2\text{O}) = -286 \, \text{kJ mol}^{-1} \]

1.8 g water is vapourised by supplying 4 kJ heat at $100^\circ\text{C}$. What is the heat of vapourisation of water at same temperature?

Which of the following methods is used to prepare dihydrogen with purity greater than 99.5 % ?

Calculate heat of formation of HCl gas from following reaction.
$\text{H}_{2(g)} + \text{Cl}_{2(g)} \rightarrow 2\text{HCl}_{(g)}$ ; $\Delta\text{H} = -194\ \text{kJ}$

Calculate change in enthalpy when 39 g acetylene is completely burnt with oxygen and enthalpy of combustion of acetylene is $-1300\ \text{kJ/mol}$. (At. mass C = 12, H = 1)