896 mL vapour of a hydrocarbon ‘A’ having carbon 87.80% and hydrogen 12.19% weighs 3.28g at STP. Hydrogenation of ‘A’ gives 2-methylpentane. Also ‘A’ on hydration in the presence of H₂SO₄ and HgSO₄ gives a ketone ‘B’ having molecular formula C₆H₁₂O. The ketone ‘B’ gives a positive iodoform test. Find the structure of ‘A’ and give the reactions involved.

This is a long answer type question as classified in NCERT Exemplar

The molar mass of the compound = 3.38 x 22400/896 =831gmol^-1

Element	Percentage	At.mass	Relative ratio	the simplest ratio
C	87.8%	12	7.31	3
H	12.19%	1	12.19	5

Thus the empirical formula of the compound is C₃H₅

Molecular formula =n x empirical formula = 831/41 x C₃H₅ = C₆H₁₀

<p><span data-teams="true">This is a long answer type question as classified in NCERT Exemplar</span></p><p><span data-teams="true">The molar mass of the compound = 3.38 x 22400/896 =831gmol^-1</span></p><table><tbody><tr><td><p>Element</p></td><td><p>Percentage</p></td><td><p>At.mass</p></td><td><p>Relative ratio</p></td><td><p>the simplest ratio</p></td></tr><tr><td><p>C</p></td><td><p>87.8%</p></td><td><p>12</p></td><td><p>7.31</p></td><td><p>3</p></td></tr><tr><td><p>H</p></td><td><p>12.19%</p></td><td><p>1</p></td><td><p>12.19</p></td><td><p>5</p></td></tr></tbody></table><p>Thus the empirical formula of the compound is C₃H₅</p><p>Molecular formula =n x empirical formula = 831/41 x C₃H₅ = C₆H₁₀</p><div><div><picture><img src="https://images.shiksha.com/mediadata/images/articles/1743663240phpszOl0f.jpeg" alt="" width="445" height="183"></picture></div></div>

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