The amount of energy required to break a bond is same as the amount of energy released when the same bond is formed. In gaseous state, the energy required for homolytic cleavage of a bond is called Bond Dissociation Energy (BDE) or Bond Strength. BDE is affected by s-character of the bond and the stability of the radicals formed. Shorter bonds are typically stronger bonds. BDEs for some bonds are given below :



Cl $$-$$ Cl (g) $$\to$$ Cl$$_{(g)}^ \bullet $$ + Cl$$_{(g)}^ \bullet $$ $$\Delta$$H$$^\circ$$ = 58 kcal mol^$$-$$1

H₃C $$-$$ Cl (g) $$\to$$ H₃C$$_{(g)}^ \bullet $$ + Cl$$_{(g)}^ \bullet $$ $$\Delta$$H$$^\circ$$ = 85 kcal mol^$$-$$1

H $$-$$ Cl (g) $$\to$$ H$$_{(g)}^ \bullet $$ + Cl$$_{(g)}^ \bullet $$ $$\Delta$$H$$^\circ$$ = 103 kcal mol^$$-$$1

For the following reaction

CH₄(g) + Cl₂(g) $$\buildrel {light} \over \longrightarrow $$ CH₃Cl(g) + HCl (g)

the correct statement is

Newman projections P, Q, R and S are shown below :



Which one of the following options represents identical molecules?

Which of the following structures has the IUPAC name

3-ethynyl-2-hydroxy-4-methylhex-3-en-5-ynoic acid?

The Fischer projection of D-erythrose is shown below :



D-erythrose and its isomers are listed as P, Q, R, and S in Column - I. Choose the correct relationship of P, Q, R, and S with D-erythrose from Column - II.