1. Tardigrade
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  4. Lucas test is given by an alcohol within 5 minutes. 0.22 g of which liberates 56 mL of CH4 at STP on treating with CH3MgI. The structure of alcohol is

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Q. Lucas test is given by an alcohol within 5 minutes. $0.22 \,g$ of which liberates 56 mL of $CH_4$ at STP on treating with $CH_3MgI$. The structure of alcohol is

AIIMSAIIMS 2017Alcohols Phenols and Ethers

Solution:

Lucas test will be given by all the given alcohols within 5 minutes as all are 2$^{\circ}$ alcohols. Exact structure can be known by molecular mass or formula of alcohol which will be obtained as follows :
Let molecular mass of alcohol be M.
$\frac{56}{22400}=\frac{0.22}{M}$ or, $M=\frac{22400\times0.22}{56}=88$
The general formula of alcohols is CnH2n + 1OH. The molecular mass 88 corresponds to the value of n = 5. Thus, the 2$^{\circ}$ alcohol is (CH3)2CHCHOHCH3.