JEE Advanced 2022 — Paper 1 — CHEM-I solution

JEE Advanced2022Paper 1CHEM-I

If the reaction sequence given below is carried out with 15 moles of acetylene, the amount of the product D formed (in g) is __________.

The yields of A, B, C and D are given in parentheses.

[Given: Atomic mass of H = 1, C = 12, O = 16, Cl = 35]

Your answer

Solution

Cyclotrimerization: 3 acetylene molecules give 1 benzene over a red-hot iron tube. From 15 mol acetylene, theoretical benzene = 5 mol; with 80% yield, A (benzene) = 4 mol.

Friedel-Crafts alkylation: benzene + isopropyl chloride / AlCl $_{3}$ gives cumene. With 50% yield from 4 mol benzene, B (cumene) = 2 mol.

Cumene hydroperoxide rearrangement (Hock process): cumene with O $_{2}$ then H $_{3}$ O $^{+}$ gives phenol and acetone. With 50% yield from 2 mol cumene, C (phenol) = 1 mol.

Acetylation: phenol + CH $_{3}$ COCl / pyridine gives phenyl acetate. With 100% yield from 1 mol phenol, D (phenyl acetate, C $_{6}$ H $_{5}$ OCOCH $_{3}$ = C $_{8}$ H $_{8}$ O $_{2}$ ) = 1 mol.

Molar mass of phenyl acetate = $8 (12) + 8 (1) + 2 (16) = 96 + 8 + 32 = 136$ g/mol.

Mass of D = $1 \times 136 = 136$ g.

← Back to full paper

Practice more CHEM-I

Concept-wise practice with instant solutions on Fundamenthol.

Start practicing →