Alcohols and Ethers - Result Question 59

64. An organic liquid ’ $A$ ’ containing $C, H$ and $O$ with boiling point $78^{\circ} C$, possessing a rather pleasant odour, on heating with concentrated sulphuric acid gives a gaseous product ’ $B$ ’ with the empirical formula, $CH _2$. ’ $B$ ’ decolourises bromine water as well as alkaline permanganate solution and takes up one mole of $H _2$ (per mole of $B$ ) in presence of finely divided nickel at high temperature. Identify the substances $A$ and $B$.

$(1979,2 M)$

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Solution:

  1. $A$ is ethanol because $B$ is an alkene (ethene).

$$ C _2 H _5 OH+\text { Conc. } H _2 SO _4 \longrightarrow CH _2=CH _2 \xrightarrow[CH _3-CH _3]{H _2 / Ni} $$

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