MCQ
Which energy diagram best represents the given reaction ?
- A
- B
- C
- ✓
✓
Answer
Correct option: D.
d
$(d)$ It is possible to interconvert cis and trans alkenes, but the $\pi$ -bond must be broken first. This requires a considerable amount of energy - around $260\, kJ\, mol^{-1}$ .One way to break the $\pi$ -bond would be to promote an electron from the $\pi$ -orbital to the $\pi^*$ -orbital. If this were to happen, there would be one electron in the bonding $\pi$ -orbital and one in the antibonding $\pi^*$ -orbital and hence no overall bonding. Electromagnetic radiation of the correct energy could promote the electron from $HOMO$ to $LUMO$. The correct energy actually corresponds to light in the ultraviolet $(UV)$ region of the spectrum. Thus, shining $UV$ light on an alkene would promote an electron from its bonding $\pi$ -molecular orbital to its antibonding $\pi^*$ -molecular orbital, thereby breaking the $\pi$ -bond (but not the $\sigma$ - bond) and allowing rotation to occur.
$(d)$ It is possible to interconvert cis and trans alkenes, but the $\pi$ -bond must be broken first. This requires a considerable amount of energy - around $260\, kJ\, mol^{-1}$ .One way to break the $\pi$ -bond would be to promote an electron from the $\pi$ -orbital to the $\pi^*$ -orbital. If this were to happen, there would be one electron in the bonding $\pi$ -orbital and one in the antibonding $\pi^*$ -orbital and hence no overall bonding. Electromagnetic radiation of the correct energy could promote the electron from $HOMO$ to $LUMO$. The correct energy actually corresponds to light in the ultraviolet $(UV)$ region of the spectrum. Thus, shining $UV$ light on an alkene would promote an electron from its bonding $\pi$ -molecular orbital to its antibonding $\pi^*$ -molecular orbital, thereby breaking the $\pi$ -bond (but not the $\sigma$ - bond) and allowing rotation to occur.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
When you ingest aspirin, it passes through your stomach, which has an acidic $pH,$ before traveling through the basic environment of your intestine. Provide the structure form as it exists in the intestine.
→Which of the following reaction is called as wurtz- fittig reaction
The basic character of the transition metal monoxides follows the order
→(Atomic no. $Ti = 22, V = 23, Cr = 24, Fe = 26$)
If a chemical reaction is accompanied by the evolution of heat, it is
The total number of possible isomers for the complex compound $\left[ {C{u^{II}}{{(N{H_3})}_4}} \right]\,\left[ {P{t^{II}}C{l_4}} \right]$ are
→For $d-$ block elements the first ionization potential is of the order
→$1{s^2}2{s^2}2{p^6}3{s^2}$ is the electronic configuration of the metal
→The reaction $CaC{O_3}$ $\rightleftharpoons$ $CaO + C{O_2}_{(g)}$ goes to completion in lime kiln because
→The reaction that occurs in a breath analyser, a device used to determine the alcohol level in a person's blood stream is
→$2 \mathrm{~K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+8 \mathrm{H}_{2} \mathrm{SO}_{4}+3 \mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O} \rightarrow 2 \mathrm{Cr}_{2}\left(\mathrm{SO}_{4}\right)_{3}+$
$3 \mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{2}+2 \mathrm{~K}_{2} \mathrm{SO}_{4}+11 \mathrm{H}_{2} \mathrm{O}$
If the rate of appearance of $\mathrm{Cr}_{2}\left(\mathrm{SO}_{4}\right)_{3}$ is $2.67 \,\mathrm{~mol}$ $\min ^{-1}$ at a particular time, the rate of disappearance of $\mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O}$ at the same time is ...... $\mathrm{mol}\, \mathrm{min}^{-1}$ (Nearest integer)
Assertion : Dinegative anion of oxygen $(O^{2-})$ is quite common but dinegative anion of sulphur $(S^{2-})$ is less common.
→Reason : Covalency of oxygen is two.