Q120 · CSIR-NET Chemistry, June 2011

Paper: CSIR-NET June 2011 · Subject: Physical Chemistry · Chapter: Group Theory · Topic: Symmetry Elements Point Groups · Marks: 2 · Difficulty: Easy

The symmetry point group of propyne is

(a)$\mathrm{C}_{3}$

(b)$\mathrm{C}_{3 \mathrm{v}}$

(c)$\mathrm{D}_{3}$

(d)$\mathrm{D}_{3 \mathrm{d}}$

Answer

Answer: B ✓ checked by 4AB · confidence high

Explanation

Propyne CH₃–C≡C–H has a C₃ axis and three σ_v planes but no σ_h or perpendicular C₂: C₃v.

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