The enthalpy of neutralization of any strong acid and strong base is constant because......

The enthalpy of formation of ethane $(C_2H_6)$ from ethylene $(C_2H_4)$ by the addition of hydrogen,where the bond energies of $C-H$,$C-C$,$C=C$,and $H-H$ are $414 \ kJ/mol$,$347 \ kJ/mol$,$615 \ kJ/mol$,and $435 \ kJ/mol$ respectively,is $........$ $kJ/mol$.

The energy required to break one mole of $Cl-Cl$ bonds in $Cl_2$ is $242 \, kJ \, mol^{-1}.$ The longest wavelength of light capable of breaking a single $Cl-Cl$ bond is $............ \, nm.$
$(c = 3 \times 10^8 \, m \, s^{-1}$ and $N_A = 6.02 \times 10^{23} \, mol^{-1}).$

The enthalpies of combustion of diamond and graphite are $-395.4 \, kJ$ and $-393.5 \, kJ$ respectively. The enthalpy of transformation of diamond to graphite is ..... $kJ$.

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

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 $kJ$)