Chemistry · Hydrocarbons
Work through this past-paper style MCQ, then read the full explanation. Practice more chemistry questions on mMCQ with adaptive drills and topic analytics.
Which xylene is most easily sulphonated:
- A
Ortho
- B
Para
- C
Meta
- D
All at the same rate
Meta-xylene is the most easily sulphonated due to the arrangement of the -CH3 groups, which enhances electron donation, making the ring more reactive to electrophiles. Ortho-xylene experiences steric hindrance due to adjacent methyl groups, reducing its reactivity. Para-xylene, while less hindered, is still less reactive than meta due to its electronic configuration. The idea that all xylenes sulphonate at the same rate is incorrect because steric and electronic factors vary with their molecular structure.
Ortho-xylene has two -CH3 groups adjacent to each other, creating steric hindrance. This makes it less favorable for electrophilic attack compared to the meta position.
Para-xylene has -CH3 groups opposite each other, which reduces steric hindrance, but it is less reactive than the meta position due to electronic effects.
Meta-xylene is the most easily sulphonated because the position of the -CH3 groups allows for greater electron donation, enhancing reactivity to electrophilic substitution.
Xylenes do not sulphonate at the same rate; differences in steric and electronic effects make some positions more reactive than others. Meta-xylene is sulphonated most easily.
Tagged under Chemistry · Hydrocarbons · 2013