When $4 \ g$ of iron is burnt to ferric oxide at constant pressure,$29.28 \ kJ$ of heat is evolved. What is the enthalpy of formation of ferric oxide in $kJ \ mol^{-1}$? (At. Wt. of $Fe = 56$)

Which of the following compounds will absorb the maximum quantity of heat when dissolved in the same amount of water? The heats of solution of these compounds at $25 \, ^\circ C$ in $kJ/mole$ of each solute are given in brackets.

The standard enthalpies of formation of $Al_{2}O_{3}$ and $CaO$ are $-1675 \ kJ \ mol^{-1}$ and $-635 \ kJ \ mol^{-1}$ respectively.
For the reaction $3 CaO + 2 Al \rightarrow 3 Ca + Al_{2}O_{3}$,the standard reaction enthalpy $\Delta_{r}H^{\circ}$ is .......... $kJ$.
(Round off to the Nearest Integer).

If the enthalpy of neutralization of $HCN$ and $NaOH$ is $-12.13 \, kJ/mol$,then the enthalpy of ionization of $HCN$ will be ...... $kJ/mol$.

The heat of neutralisation of an acid by a base is highest when:

The enthalpy of solution of anhydrous $CuSO_4$ is $-15.9 \, kcal$ and that of $CuSO_4 \cdot 5H_2O$ is $2.8 \, kcal$. The enthalpy of hydration of $CuSO_4$ is ..... $kcal$. (in $.7$)