In order to decompose $9 \ g$ of water,$142.5 \ kJ$ of heat is required. Hence,the enthalpy of formation of water is ...... $kJ/mol$.

Standard molar enthalpy of formation of $CO_2$ is equal to

Calculate the heat required to convert $9 \ g$ of liquid water to water vapor using the following equations:
$H_{2(g)} + 1/2 O_{2(g)} \longrightarrow H_2O_{(g)} \quad \Delta H = -57 \ kCal$
$H_{2(g)} + 1/2 O_{2(g)} \longrightarrow H_2O_{(l)} \quad \Delta H = -68.3 \ kCal$ (in $kCal$)

From the following thermochemical equations,find out the heat of ionisation $Z$ for a weak acid $HA$:
$HA \to A^{-} + H^{+} , \Delta H = Z$
$H^{+} + OH^{-} \to H_2O , \Delta H = X$
$HA + OH^{-} \to A^{-} + H_2O , \Delta H = Y$

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.

When equal volumes of molar hydrochloric acid $(HCl)$ and sulfuric acid $(H_2SO_4)$ are neutralized by a dilute $NaOH$ solution,the heat produced is $x \ KCal$ and $y \ KCal$ respectively. Which of the following is correct?