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Structural formula -Part 5

structural formula-

source : science jrank.org

structural formula-

Q 1– Molecular formula of compound ‘A’ is C2H5O2N. Compound  ‘A’ on reduction gives primary amine ‘B’ which gives ethanol  with HNO2. Compd ‘B’ gives bad smelling compound with CHCl3 & alcoholic KOH  to form compound ‘C’. ‘C’ on reduction gives ethyl methyl amine. Give name & formula of  A,B & C.

Ans.

Compd ‘A’ on reduction gives primary amine , so ‘A’ is nitroalkane & ‘B’ is ethyl amine.

C2H5NO2 + 6[H] —-> C2H5NH2 +2H2O

‘A’

(nitro alkane)

C2H5NH2 +HNO2—->C2H5OH +N2 +H2O

‘B’                                         ethanol

C2H5NH2 +CHCl3 +3 KOH—–>C2H5NC +3KCl +H2O

‘C’

(Ethyl isocyanide)

C2H5NC +4[H] —–>C2H5NHCH3

‘C’                            Ethyl methyl amine

‘A’ is C2H5NO2 ( Nitroethane) ; ‘B’ is C2H5NH2 (ethyl amine or amino ethane) ; C is  C2H5NC (ethyl iso cyanide).

Q 2– Compound ‘A’ has molecular formula CH2O  .Compound ‘A’reduces fehling solution . It reacts with NaOH to form alc. ‘B’ & sodium salt of acid ‘C’. Compound ‘A’ on reduction  gives ‘B’. Give name & formula of A ,B & C.

Ans.

‘A’reduces fehling solution therefore it is an aldehyde i.e HCHO

HCHO +2CuO —–> HCOOH + Cu2O

HCHO gives  cannizarro’s reaction

HCHO +NaOH —->HCOONa    +       CH3OH

‘A’                            sodium formate’C’   ‘B’

‘A’ on reduction gives ‘B’

HCHO +H2 —-> CH3OH

‘A’                             ‘B’

‘A’ is HCHO ( formaldehyde  or methanal); ‘B’ is CH3OH (methyl alcohol or methanol) ;’C’ is HCOONa (sodium formate).

Q 3– Molecular formula of compound is C3H6O. It gives addition reaction with HCN & NaHSO3 but it does not give red colour with Schiff’s reagent.Give name & formula of compound.

Ans.

It gives addition reaction with HCN & NaHSO3 therefore it may be aldehyde or ketone. But it does not give red colour with Schiff’s reagent so it is a ketone or acetone.

CH3COCH3 +HCN —->CH3C(OH)CN. CH3

acetone                               acetone cyanohydrin

CH3COCH3 + NaHSO3 —->CH3C(OH)SO3Na.CH3

acetone sodium bisulphite compd

Compound is CH3COCH3 ( acetone or propanone) Ans.

Q 4– Molecular formula of compound is CH4N2O.It reacts with HNO2 to form N2, CO2 & H2O. Give name &formula ,

Ans.

It gives  N2, CO2 & H2O with HNO2 . So  compd have -NH2 gr. Compound is urea.

NH2CONH2 + 2HNO2—–> 2 N2 +CO2 +3H2O

urea

Compound is NH2CONH2 (urea) .


 

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Saroj Bhatia: Dr. Saroj Bhatia is an Ph.D in chemistry who has been teaching chemistry for over a decade. Currently she is a respected principal of a renowned college in her hometown. She took this medium for online users. Her proudest achievement is helping people learn chemistry.
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