The hydrocarbon (X) with molar mass 80 g mol -1 and 90 \% carbon has degree of unsaturation.

Chemistry · Hydrocarbons

JEE Main 2025 — 24 January, Evening Shift — Question 45

The hydrocarbon (X) with molar mass $80 \mathrm{~g} \mathrm{~mol}^{-1}$ and $90 \%$ carbon has ___degree of unsaturation.

Numerical answer — enter this value.

Mass of carbon $=\frac{80 \times 90}{100}=72 \mathrm{gm}$

Number of C-atoms $=\frac{72}{12}=6$

Mass of hydrogen $=\frac{80 \times 10}{800}=8 \mathrm{gm}$

Number of H-atoms $=\frac{8}{1}=8$

So molecular formula $\mathrm{C}_{6} \mathrm{H}_{8}$

D.U. $=6+1-8 / 2=7-4=3$

Answer key and solution verified before publishing.

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