JEE Main Previous Year Papers Questions With Solutions Chemistry Nitro,Amine and Azo Compounds
1.When primary amine reacts with chloroform in etharioicKOH then the product is (2002)
1) an isocyanide 2) an aldehyde
3) a cyanide 4) an alcohol
2.The reaction of chloroform with alcoholic KOH and p-toludine forms (2003)
3.The correct order of increasing basic nature for the bases NH3. CH3NH2 and (CH3)2NH is(2003)
1)(CH3 )2 NH < NH3 < CH3NH2
2)NH3 < CH,NH2 < (CH3 )2 NH
3)CH3NH2 < (CH3 )2 NH < NH3
4)CH3NH2 < NH3 < (CH3)2 NH
Ans.(2) More is the no. of +1 groups attached to N atom greater is the basic character.
4.Ethyl isocyanide on hydrolysis in acidic medium generates (2003)
1)propanoic acid and ammonium salt .
2)ethanoic acid and ammonium salt
3)methylamine salt and ethanoic acid
4)ethylamine salt and methanoic acid
5.The ammonia evolved from the treatment of 0.30 g of an organic compound for the estimation of nitrogen was passed in 100 mL of 0.1 M sulphuric acid. The excess of acid required 20 mL of 0.5M sodium hydroxide solution hydroxide solutio for complete neutralization. The organic compound is 1)acetamide 2) thiourea (2004)
3) urea 4) benzamide
Ans.(3) Urea has C and N atoms in the ratio 1:2.
6.Which of the following is the strongest base?
Ans.(2)1° aliphalic amine.
7.Which one of the following methods is neither meant for the synthesis nor for separation of amines ? (2005)
1) Hinsberg method 2) Hofmann method 3) Wurtz reaction 4) Curtius reaction
Ans.(3) Alkanes are obtained in Wurtz reaction.
8.Amongst the following the most basic compound is (2005)
1) benzylamine 2) aniline
3) acetanilide 4) p-nitroaniline
Ans.(1) -NH2 group is not linked with benzene ring
9.An organic compound having molecular mass 60 is found to contain C=20%, H=6.67% and N=46.67% while rest is oxygen. On heating it gives NH3 alongwith a solid residue. The solid residue give violet colour with alkaline copper sulphate solution. The compound is (2005)
1) CH3NCO 2) CH3 CONH2
3) (NH2)2CO 4) CH3CH2CONH2
Ans. (3)Emperical formula CH4ON2.
10.Fluorobenzene (C6H5F) can be synthesized in the laboratory (2006)
1)by heating phenol with HF and KF
2)from aniline by diazotisation followed by heating the diazonium salt with HBF4
3)by direct fluorination of benzene with F2 gas
4)by reacting bromobenzene with NaF solution
Ans.(2) Fluordrenzene is syntherised fro C6H5HBF4
11. CH3CH2NH2+CHa3+3KOH –>(A)+(B) + 3H20 In the chemical reaction, the compound (A) and (B) are respectively (2007)
1)C2H5CN and 3KCl
2)CH3CH2CONH2 and 3KCl
3)C2H5NC and K2 C03
4)C2H5NC and 3KCl
Ans.(4) It is example of carbylamine reaction. The product will be C2H5
12.Which one of the following is the strongest base in aqueous solution ? (2007)
1) Trimethylamine 2) Aniline
3) Dimethylamine 4) Methylamine
Ans.(3) In aqueous solution basicity order of 1°, 2° and 3° amine with methyl group is 2° > 1° > 3°.In case of aniline lone pair of nitrogen is involved in resonance, so it is weaker base than aliphatic amines.
13.Toluene is nitrated and the resulting product ‘ is reduced with tin and hydrochloric acid. The product so obtained is diazotised and then heated with cuprotis bromide. The reaction mixture so formed contains (2008)
1)mixture of o – and p-bromotoluences
2)mixture of o- and p-dibromobenzenes
3)mixture of o- and p-bromoanilines
4)mixture of o-and m-bromotoluenes
14.In the chemical reactions, the compound ‘A’ and ‘B’ respectively are (2010)
15.A compound with molecular mass 180 is acylated with CH3COC/ to get a compound * with molecular mass 390. The number of amino groups present per molecule of the former compound is (2013)
1) 2 2) 5 3) 4 4)6
16.On heating an aliphatic primary amine with chloroform and ethanolic potassium hydroxide, the organic compound formed is (2014)
1) an alkyl isocyanide 2) an alkanol
3) an alkanediol 4) an alkyl cyanide
Ans.(1) R – NH2 + CHC13 + KOH -> R – NC Alkylisocyanide is obtained.
17.Considering the basic strength of amines in aqueous solution, which one has the smallest pKb vale ?(2014)
1)C6H5NH2 2) (CH3)2NH
3) CH3NH2 4) (CH3)3N
Ans.(2) (CH3)2NH is a stronger base in aqueous medium than Me3 So its pKb value is smallest.
Ans.(3) Sandmayer reaction.