When $1 \ mol$ of $NH_4OH$ reacts with $1 \ mol$ of $HCl$,the amount of heat released is.....

Calculate the change in enthalpy when $39 \ g$ of acetylene is completely burnt with oxygen,given that the enthalpy of combustion of acetylene is $1300 \ kJ \ mol^{-1}$. (in $kJ$)

From the given diagram, the enthalpy change $\Delta_r H$ for the reaction $C \rightarrow A$ is:

Which of the following reactions defines $\Delta H_f^o$?

If the heat of neutralization of an acid-base reaction is $56 \ kJ \ mol^{-1}$,then the substances could be:

If at $298 \, K$ the bond energies of $C-H, C-C, C=C$ and $H-H$ bonds are respectively $414, 347, 615$ and $435 \, kJ \, mol^{-1}$,the value of enthalpy change for the reaction $H_2C=CH_{2(g)} + H_{2(g)} \to H_3C-CH_{3(g)}$ at $298 \, K$ will be $.... \, kJ$.