Question

Arrange the following groups in order of increasing priority. (a) \(-\mathrm{CH}_{3}-\mathrm{H}-\mathrm{Br}-\mathrm{CH}_{2} \mathrm{CH}_{3}\) (b) \(-\mathrm{OCH}_{3}-\mathrm{CH}\left(\mathrm{CH}_{3}\right)_{2}-\mathrm{B}\left(\mathrm{CH}_{2} \mathrm{CH}_{3}\right)_{2}-\mathrm{H}\) (c) \(-\mathrm{CH}_{3}-\mathrm{CH}_{2} \mathrm{OH}-\mathrm{CH}_{2} \mathrm{NH}_{2} \quad-\mathrm{CH}_{2} \mathrm{Br}\)

Short answer

Question: Arrange the following groups in order of increasing priority: (a) -CH3, (b) -OCH3, (c) -CH2OH.

Step-by-step solution

Identify the first atom in each group

List the first atom of each group: (a) \(C\) from \(-CH_3\) (b) \(O\) from \(-OCH_3\) (c) \(C\) from \(-CH_3\)

Compare the atomic numbers of the first atoms

Compare the atomic numbers of the first atoms in each group to determine their priority: (a) Carbon has an atomic number of 6 (b) Oxygen has an atomic number of 8 (c) Carbon (again) has an atomic number of 6 Since there is a tie between group (a) and group (c), we need to look at the second atoms in these groups and compare their atomic numbers. (a) Second atom: \(H\) from \(-H\) -> atomic number: 1 (c) Second atom: \(O\) from \(-CH_2OH\) -> atomic number: 8 Comparing the second atoms in group (a) and group (c), we can see that group (c) has higher priority due to the oxygen atom. Therefore, the order of increasing priority is: \(-CH_3 - H - Br - CH_2CH_3 < -OCH_3 - CH(CH_3)_2 - B(CH_2CH_3)_2 - H < -CH_3 - CH_2OH - CH_2NH_2 - CH_2Br\)