Exam

JEE Main

Year

2025

Date

24 January

Shift

Evening Shift

Subject

Chemistry

Chapter

Some Basic Concepts of Chemistry

JEE Main 2025 · 24 January · Evening Shift · Chemistry · Some Basic Concepts of Chemistry

The hydrocarbon (X) with molar mass 80 ~g ~mol^ -1 and 90 \% carbon...

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

Step-by-step solution

$\therefore$ Empirical formula is $\mathrm{C}_3 \mathrm{H}_4$ Molecular mass $=80 \mathrm{~g} \mathrm{~mol}^{-1}$. Molecular formula $=\left(\mathrm{C}_3 \mathrm{H}_4\right)_{\mathrm{n}} \mathrm{n}=\frac{\text{ Molecular mass }}{\mathrm{EF} \text{ mass }}=\frac{80}{40}=2 \therefore$ Molecular formula is $\mathrm{C}_6 \mathrm{H}_8$ Degree of unsaturation $=\frac{2 \times 6+2-8}{2}=3$