The $\Delta_f H^{\circ}$ of $AO_{(s)}$, $BO_{2(g)}$ and $ABO_{3(s)}$ is $-635$, $x$ and $-1210 \ kJ \ mol^{-1}$ respectively.
$ABO_{3(s)} \rightarrow AO_{(s)} + BO_{2(g)} ; \Delta_r H^{\circ} = 175 \ kJ \ mol^{-1}$.
What is the value of $x$ (in $kJ \ mol^{-1}$) ?

For the reaction $OF_{2(g)} \to O_{(g)} + 2F_{(g)}$,$\Delta_{rxn}H$ is $368 \ kJ$. What is the average $O-F$ bond energy in $kJ/mol$?

The enthalpy changes for the following reactions are given:
$Cl_{2(g)} = 2Cl_{(g)}, 242.3 \, kJ \, mol^{-1}$; $I_{2(g)} = 2I_{(g)}, 151.0 \, kJ \, mol^{-1}$
$ICl_{(g)} = I_{(g)} + Cl_{(g)}, 211.3 \, kJ \, mol^{-1}$; $I_{2(s)} = I_{2(g)}, 62.76 \, kJ \, mol^{-1}$
Given that the standard states of iodine and chlorine are $I_{2(s)}$ and $Cl_{2(g)}$,the standard enthalpy of formation for $ICl_{(g)}$ is $...... \, kJ \, mol^{-1}$.

When $2 \, mol$ of $C_2H_6$ is completely combusted,$3129 \, kJ$ of heat is released. The heat of formation of $C_2H_6$ is ..... $kJ/mol$. Given that $\Delta H_f$ for $CO_2$ and $H_2O$ are $-395 \, kJ/mol$ and $-286 \, kJ/mol$ respectively.

The heat of neutralization for $2 \ moles$ of $\text{LiOH}$ and $1 \ mole$ of $H_2SO_4$ at $25^{\circ} C$ is $-69.6 \ kJ$. The heat of ionisation of $\text{LiOH}$ will be nearly $:-$

When $600 \; mL$ of $0.2 \; M \; HNO_3$ is mixed with $400 \; mL$ of $0.1 \; M \; NaOH$ solution in a flask,the rise in temperature of the flask is $\dots \times 10^{-2} \; ^{\circ}C$. (Enthalpy of neutralisation $= 57 \; kJ \; mol^{-1}$ and Specific heat of water $= 4.2 \; J \; K^{-1} \; g^{-1}$) (Neglect heat capacity of flask)