From the given diagram, the enthalpy change $\Delta_r H$ for the reaction $C \rightarrow A$ is:

Which of the following equations is used to calculate the standard enthalpy change of a reaction $(\Delta_r H^\circ)$?

The heat of neutralisation of $NaOH$ and $HCl$ is $-57.46 \, kJ/eq$. What is the heat of ionisation of water in $kJ/mol$?

What amount of energy (in $KJ$) is released in the combustion of $5.8\, g$ of $C_4H_{10}\,(g)$?
$2 C_4H_{10}(g) + 13 O_2(g) \to 8 CO_2(g) + 10 H_2O(l)$; $\Delta H^o = -5756\, KJ$

The enthalpy change $(\Delta H)$ for the process $N_2H_{4(g)} \to 2N_{(g)} + 4H_{(g)}$ is $1724 \ kJ \ mol^{-1}$. If the bond energy of $N-H$ bond in ammonia is $391 \ kJ \ mol^{-1}$,what is the bond energy of $N-N$ bond in $N_2H_4$ in $kJ \ mol^{-1}$?

Enthalpy of formation of $CO_{(g)}$,$CO_{2(g)}$,$N_2O_{(g)}$ and $N_2O_{4(g)}$ are $-110$,$-393$,$81$,and $9.7 \ kJ \ mol^{-1}$ respectively. Calculate $\Delta_r H$ for the following reaction: $N_2O_{4(g)} + 3 CO_{(g)} \longrightarrow N_2O_{(g)} + 3 CO_{2(g)}$