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Chemistry · Hydrocarbons

JEE Main 2026 — 2 April, Morning Shift — Question 58

One mole of an alkane (x) requires 8 mole oxygen for complete combustion. Sum of number of carbon and hydrogen atoms in the alkane ( x ) is ____\_\_\_\_ .

Answer: 17

Numerical answer — enter this value.

Step-by-step solution

CnH2n+2+(3n+12)O2→nCO2+(n+1)H2O\quad \mathrm{C}_{\mathrm{n}} \mathrm{H}_{2 \mathrm{n}+2}+\left(\frac{3 \mathrm{n}+1}{2}\right) \mathrm{O}_{2} \rightarrow \mathrm{nCO}_{2}+(\mathrm{n}+1) \mathrm{H}_{2} \mathrm{O}

13n+12=8⇒3n+1=16⇒3n=15n=5\begin{gathered} 1 \frac{3 n+1}{2}=8 \Rightarrow 3 n+1=16 \Rightarrow 3 n=15 n=5 \end{gathered}

So alkane is C5H12⇒17\mathrm{C}_{5} \mathrm{H}_{12} \Rightarrow 17

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Paper
2 April, Morning Shift
Subject
Chemistry
Chapter
Hydrocarbons
Topic
Preparation of alkanes
One mole of an alkane (x) requires 8 mole oxygen for complete… | JEE Main 2026 PYQ with Solution · DhiX AI