The enthalpy of solution of $NaOH_{(s)}$ in water is $-41.6 \ kJ \ mol^{-1}$. When $NaOH_{(s)}$ is dissolved in water,the temperature of the water will ..........

Calculate the enthalpy of formation of ethylene $(C_2H_4)$ from the following data:
$I. C_{(graphite)} + O_{2(g)} \rightarrow CO_{2(g)}; \Delta H = -393.5 \ kJ$
$II. H_{2(g)} + \frac{1}{2}O_{2(g)} \rightarrow H_2O_{(l)}; \Delta H = -286.2 \ kJ$
$III. C_2H_{4(g)} + 3O_{2(g)} \rightarrow 2CO_{2(g)} + 2H_2O_{(l)}; \Delta H = -1410.8 \ kJ$ (in $kJ$)

For which of the following reactions does the heat of reaction represent the bond energy of $HCl$?

Identify the factor from the following on which the heat of reaction does not depend.

If the enthalpy of atomisation for $Br_{2(l)}$ is $x \ kJ/mol$ and the bond enthalpy for $Br_{2(g)}$ is $y \ kJ/mol$,what is the relation between them?

Enthalpy of sublimation of a substance is equal to