When the aqueous solution of $0.5 \, mole$ of $HNO_3$ is mixed with $0.3 \, mole$ of $OH^{-}$ solution,what will be the liberated heat in $kJ$? (Enthalpy of neutralization is $= 57.1 \, kJ \, mol^{-1}$)

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 $kJ$)

Given:
$(A) \ 2 \ CO_{(g)} + O_{2(g)} \rightarrow 2 \ CO_{2(g)} \quad \Delta H_1^\theta = -x \ kJ \ mol^{-1}$
$(B) \ C \ (\text{graphite}) + O_{2(g)} \rightarrow CO_{2(g)} \quad \Delta H_2^\theta = -y \ kJ \ mol^{-1}$
The $\Delta H^\theta$ for the reaction $C \ (\text{graphite}) + \frac{1}{2} O_{2(g)} \rightarrow CO_{(g)}$ is:

Given that the bond energies of $N \equiv N$ is $946 \ kJ \ mol^{-1}$,$H-H$ is $435 \ kJ \ mol^{-1}$,$N-N$ is $159 \ kJ \ mol^{-1}$,and $N-H$ is $389 \ kJ \ mol^{-1}$,calculate the enthalpy of formation for the gas phase reaction $N_2 + 2H_2 \rightarrow N_2H_4$ in $kJ \ mol^{-1}$.

How much heat in $kJ$ is produced by the combustion of $15.5 \, g$ of propane? ${C_3H_8} + 5{O_2} \to 3{CO_2} + 4{H_2O}; \Delta{H^o} = -2219 \, kJ/mol$

At constant pressure, the heat of formation of a compound is not dependent on temperature, when