The heats of solution of anhydrous $CuSO_4$ and $CuSO_4 \cdot 5H_2O$ are $-15.89 \, kcal \, mol^{-1}$ and $2.80 \, kcal \, mol^{-1}$ respectively. What is the heat of hydration of anhydrous $CuSO_4$ in $kcal \, mol^{-1}$?

Based on the following thermochemical equations,find the value of $x$ in $kJ$.
$(i) \ H_2O_{(g)} + C_{(s)} \to CO_{(g)} + H_{2(g)} ; \Delta H = 131 \ kJ$
$(ii) \ CO_{(g)} + \frac{1}{2} O_{2(g)} \to CO_{2(g)} ; \Delta H = -282 \ kJ$
$(iii) \ H_{2(g)} + \frac{1}{2} O_{2(g)} \to H_2O_{(g)} ; \Delta H = -242 \ kJ$
$(iv) \ C_{(s)} + O_{2(g)} \to CO_{2(g)} ; \Delta H = -x \ kJ$

If heat of neutralization is $-13.7 \, KCal$ at $25 \, ^oC$ and $\Delta H_f^o (H_2O) = -68 \, KCal$,then the standard enthalpy of formation of $OH^{-}$ will be.....$KCal$. (in $.3$)

Given the reactions:
$C + \frac{1}{2}O_2 \to CO : \Delta H = -12 \ kJ$
$CO + \frac{1}{2}O_2 \to CO_2 : \Delta H = -10 \ kJ$
For the reaction $C + O_2 \to CO_2 : \Delta H = x \ kJ$,the value of $x$ is: (in $kJ$)

The total enthalpy change in a chemical reaction is equal to the algebraic sum of the enthalpy changes of the individual steps of the reaction. This statement is associated with which scientist?

$2.1 \ g$ of $Fe$ combines with $S$ evolving $3.77 \ kJ$. The heat of formation of $FeS$ in $kJ/mol$ is