Alcohols and Ethers - Result Question 2
####2. The synonym for water gas when used in the production of methanol is
(2019 Main, 10 April I)
(a) natural gas
(b) laughing gas
(c) syn gas
(d) fuel gas
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Answer:
Correct Answer: 2. (d)
Solution:
- The production of methanol from water gas is as follows:
$$ \underset{\substack{\text { Water gas } \ \text { or } \ \text { syn gas }}}{\left[CO+H _2\right]}+H _2 \xrightarrow[300 \text { atm, } 300^{\circ} C]{ZnO+Cr _2 O _3} \underset{\text { Methanol }}{CH _3 OH} $$
It is an industrial process used for the production of methanol where volume ratio of the reactant gases is maintained as: syn gas : $H _2=2: 1$ and $ZnO-Cr _2 O _3$ act as catalysts Thus, water gas is also called syn gas because it is used for synthesis of methanol.
Key Idea $LiAlH _4$ reagent is used for the reduction of $-CHO$,
. It does not reduce double bonds.
The reaction of an ester with $LiAlH _4$ produces two alcohols, one corresponding to the acyl portion of the ester and one corresponding to the alkyl portion.
Thus, the major product of the given reactant
$CH _3 CH=CHCOCH _3$ in presence of $LiAlH _4$ is $CH _3 CH=CHCH _2 OH$ and $CH _3 OH$. The reaction proceeds through following mechanism.
Mechanism
