If $38.55 \ kJ$ of heat is absorbed when $6.0 \ g$ of $O_2$ reacts with $ClF$ according to the reaction $2ClF_{(g)} + O_{2(g)} \longrightarrow Cl_2O_{(g)} + OF_{2(g)}$. What is the standard enthalpy of reaction (in $kJ$)?

When ethyne is passed through a red hot tube,the formation of benzene takes place :-
$\Delta H_{f(C_2H_2)(g)}^o = 230 \ kJ \ mol^{-1}$
$\Delta H_{f(C_6H_6)(g)}^o = 85 \ kJ \ mol^{-1}$
Calculate the standard heat of trimerisation of ethyne to benzene.
$3C_2H_{2(g)} \to C_6H_{6(g)}$
......$kJ \ mol^{-1}$

The energy absorbed by each molecule $(A_2)$ of a substance is $4.4 \times 10^{-19} \ J$ and bond energy per molecule is $4.0 \times 10^{-19} \ J.$ The kinetic energy of the molecule per atom will be $...... \times 10^{-20} \ J$

The heat of formation of methane $C_{(s)} + 2H_{2(g)} \to CH_{4(g)}$ at constant pressure is $-18500 \ cal$ at $25 \ ^oC$. The heat of reaction at constant volume would be (in $cal$)

The enthalpy of neutralization of $NH_4OH$ with $HCl$ is $-51.40 \, kJ/equiv$. The enthalpy of dissociation of $NH_4OH$ is ..... $kJ$.

One mole of ethanol $(l)$ was completely burnt in oxygen to form $CO_{2(g)}$ and $H_2O_{(l)}$. What is the $\Delta_r H^{\ominus}$ (in $kJ \ mol^{-1}$) for this reaction?
(The standard enthalpy of formation $(\Delta_f H^{\ominus})$ of $C_2H_5OH_{(l)}$,$CO_{2(g)}$ and $H_2O_{(l)}$ is respectively $-277, -393$ and $-286 \ kJ \ mol^{-1}$.)