Question 1

The final product in following reaction Y is, CH _3 CH = CH _2 [ (ii) NaBH _4] (i) ( CH _3 COO )_2 Hg , CH _3 OH Y

Accepted Answer

The complete reaction is as follows,

Question 2

In the Victor-Meyer's test, the colour given by 1^ .2^ and 3^ alcohols are respectively:

Accepted Answer

Victor Meyer's test: The various steps involved are (i) RCH _2 OH HI RCH _2 I AgNO _2 RCH _2 NO _2 (ii) (iii) R _3 COH HI R _3 CI AgNO _2 R _3 CNO _2 - HNO _2 No reaction KOH Colourless

Question 3

What is X in the following reaction? CO +2 H _2 x CH _3 OH

Accepted Answer

The given reaction is for the industrial preparation methanol from a mixture of carbon monoxide and hydrogen . In the reaction the gaseous mixture is subjected to 200 atmosphere and then passed over heated catalyst mixture of ZnO and Cr _2 O _3 kept at 573-673 ~K . This reaction results the formation of methanol vopours which are then condensed to liquid state.

Question 4

An unknown alochol is treated with the "Lucas reagent" to determine whether the alcohol is primary, secondary or tertiary. Which alcohol reacts fastest and by what mechanism :

Accepted Answer

The reaction of alcohol with Lucas reagent is mostly an S _ N 1 mechanism reaction and the rate of reaction is directly proportional to the carbocation stability formed in the reaction, hence tertiary alcohol will react fastest.

Question 5

Which will not result in the formation of anisole?

Accepted Answer

[ PtCl _2 ( NH _3 )_4 ] Br _2 and [ PtBr _2 ( NH _3 )_4 ] Cl _2 are ionisation isomers.

Question 6

Which method is useful for the synthesis of ether?

Accepted Answer

At 443 ~K compound in (d) will produce propene. In (a) alkene will be produced as tertiary halide and strong base favours elimination. In (b) reaction is not possibie at room temperature as due to resonance C - Cl bond has partial double bond character which is very difficult to break.

Question 7

In the reaction: Which of the following compounds will be formed?

Accepted Answer

Answer option index: 1

Question 8

On reaction with sodium, 1 mol of a compound X gives 1 ~mol of H _ 2 . Which one of the following compounds might be X ?

Accepted Answer

Since 1 mole of compound Xreacts with Na to evolve 1 mole of H _ 2 gas, therefore the compound should have 2 active hydrogen atoms per mole which is possible only in option d. array l CH _ 2 OHCH _ 2 CH _ 2 CH _ 2 OH +2 Na \ NaOCH _ 2 CH _ 2 CH _ 2 CH _ 2 ONa +2 H array

Alcohols Phenols and Ethers — Previous Year Questions & Solutions