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 bond energies of $H-H$ and $Cl-Cl$ are $430 \ kJ \ mol^{-1}$ and $240 \ kJ \ mol^{-1}$ respectively. If the $\Delta H_f$ (enthalpy of formation) of $HCl$ is $-90 \ kJ \ mol^{-1}$,what is the $H-Cl$ bond energy in $kJ \ mol^{-1}$?

The mutual heat of neutralisation of $40 \, g$ of $NaOH$ and $60 \, g$ of $CH_3COOH$ will be

What will be the standard heat of reaction for the reaction $C_2H_{6(g)} + 7/2 O_{2(g)} \to 2CO_{2(g)} + 3H_2O_{(l)}$ if the standard heat of combustion of $C_{(s)}$ and $H_{2(g)}$ are $-393.5 \ kJ/mol$ and $-285 \ kJ/mol$ respectively,and the standard heat of formation of $C_2H_{6(g)}$ is $-88.2 \ kJ/mol$?

Given below are two statements: One is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$
Assertion $(A)$: Enthalpy of neutralisation of strong monobasic acid with strong monoacidic base is always $-57 \ kJ \ mol^{-1}$.
Reason $(R)$: Enthalpy of neutralisation is the amount of heat liberated when one mole of $H^{+}$ ions furnished by acid combine with one mole of $OH^{-}$ ions furnished by base to form one mole of water.
In the light of the above statements,choose the correct answer from the options given below.

The net enthalpy change of a reaction is the amount of energy required to break all the bonds in reactant molecules minus the amount of energy required to form all the bonds in the product molecules. What will be the enthalpy change for the following reaction: $H_{2(g)} + Br_{2(g)} \to 2HBr_{(g)}$? Given that the bond energy of $H_2$,$Br_2$,and $HBr$ is $435 \ kJ \ mol^{-1}$,$192 \ kJ \ mol^{-1}$,and $368 \ kJ \ mol^{-1}$ respectively.