Chemistry - Purification And Characteristics of Organic Compounds
Exam Duration: 45 Mins Total Questions : 30
The elements of nitrogen and ulphur are present in an organic compound.which of the sodium compounds(is/are)present in the sodium extract on fusing it with sodium?
- (a)
thicocyante
- (b)
cyanide and sulphide
- (c)
sulphite and cyanide
- (d)
nitrate and cyanide
An organic compound is found to contain C=39.9%,H=6.7%,O=53.4%. Its empirical formula is
- (a)
CHO
- (b)
CHO2
- (c)
CH2O2
- (d)
CH2O
In Which of the following compounds nitrogen cannot be tested by lassaigne's test
- (a)
C6H8O
- (b)
CH3CONH2
- (c)
NH2CONH2
- (d)
CH3NO2
A mixture of water and alcohol can be seperated by
- (a)
eveporation
- (b)
decantation
- (c)
titration
- (d)
fractional distillation
Which of the following is blood red compound in quantitative estimation of nitrogen and sulphur together?
- (a)
Fe4[Fe(CN)6]3
- (b)
Fe(SCN)3
- (c)
FeSCN
- (d)
NA2S,NACN
Distillation is a Process Which involves
- (a)
eveporation
- (b)
condensation
- (c)
evaporation followed by condensation
- (d)
neither evaporation nor condensation
Two solids Which are soluble in same to different extent may be seperated by
- (a)
crystllisation
- (b)
evaporation
- (c)
fractional crystallisation
- (d)
sublimation
If two liquids hve widely different boiling points they may be seperated by
- (a)
distillation
- (b)
steam distillation
- (c)
sublimation
- (d)
evaporation
Seperation of two substances by fractional crystallisation depends on the difference in their
- (a)
densities
- (b)
solubilities
- (c)
volatility
- (d)
crystalline shapes
Napththalene is volatile solid.It is best purified by
- (a)
crystallisation
- (b)
distillisation
- (c)
steam distillisation
- (d)
sublimation
A dibasic acid containing C,H and O Was found to contain C = 26.7% and H = 2.2%. The vapour density of diethyl ester was found to be 73. What is moleculer formula of acid?
- (a)
CH2O2
- (b)
C2H2O4
- (c)
C3H3O4
- (d)
C4H4O4
In Lassaigne's test for nitrogen,the blue colour is due to the formation of
- (a)
Potassium ferrocyanide
- (b)
Sodium cyanide
- (c)
Sodium ferrocyanide
- (d)
Ferri-ferrocyanide
Nitrogen in an organic compound can be estimated by
- (a)
Kjeldahl's method only
- (b)
Duma's method only
- (c)
both the mothods
- (d)
NONE OF THESE METHODES
When petroleum is heated gradually, first batch of vapours evolved will be rich in
- (a)
Kerosene
- (b)
Petroleum ether
- (c)
Diesel
- (d)
lubricating oil
The sinplest formula of a compound containing 50% of element X (at. wt. 10) and 50% of element Y (at. Wt. 10) is
- (a)
XY
- (b)
XY2
- (c)
X2Y
- (d)
X2Y32
0.2 g of an organic compound on complete combustion produces 0.18 g of water , then the percentage of hydrogen in it is
- (a)
5
- (b)
10
- (c)
20
- (d)
25
If 0.32 g of an organic compound containing sulphur produces 0.233 g of BaSO4, then the percentage of sulphur in it is
- (a)
10
- (b)
15
- (c)
20
- (d)
25
In a Lassigne's test for sulphur in the organic compound with sodium nitroprusside solution the purple colour formed is due to
- (a)
Na4[Fe(CN)5NOS]
- (b)
Na3[Fe(CN)5S]
- (c)
Na2[Fe(CN)5NOS]
- (d)
Na3[Fe(CN)6].
An organic substance from its aqueous solution can be seperated by
- (a)
Distillation
- (b)
Steam distillation
- (c)
Solvent extraction
- (d)
Fractional distillation
Positive Belistein test shows that
- (a)
halogen is urely present
- (b)
halogen is absent
- (c)
halogen may be present
- (d)
NONE OF THESE
In Lassaigne test thiourea is converted into
- (a)
NACNS
- (b)
Na2S
- (c)
NACN
- (d)
Na2SO4
Chromatography is used for the purification of
- (a)
Solids
- (b)
Gases
- (c)
Liquids
- (d)
ALL THE ABOVE
The technique used for the separation of acetone and methanol is
- (a)
steam distillation
- (b)
vacuum distillation
- (c)
fractional distillation
- (d)
simple distillation
The addition of sodium nitroprusside solution to the Lassaigne's solution produces violet colouration. This signifies the presence of
- (a)
nitrogen
- (b)
sulphur
- (c)
chlorine
- (d)
phosphorus
Air contains 20% O2 by volume. The volume of air that will be required for 100cc of acetylene is
- (a)
1250cc
- (b)
1064cc
- (c)
212.8 cc
- (d)
500 cc
Which one of the following compounds cannot be formed on the fusion of thiourea with metallic sodium?
- (a)
Na2S
- (b)
NaCNS
- (c)
NaCN
- (d)
Na2SO4
The compound ClCH2COOH was heated with fuming HNO3 and AgNO3 in a Carius tube. A white precipitate is formed after filteration and washing of the reaction mixture. The white precipitate formed is
- (a)
Ag2SO4
- (b)
AgNO3
- (c)
ClCH2COOAg
- (d)
AgCl
For the estimation of nitrogen, 1.4g of an organic compound was digested by Kjeldahl's method and evolved ammonia was absorbed in 60mL of \(M\over 10\)sulphuric acid. The unreacted acid required 20mL of \(M\over 10\) sodium hydroxide for complete neutralisation. The percentage of nitrogen in the compound is
- (a)
6%
- (b)
10%
- (c)
3%
- (d)
5%
29.5 mg of an organic compound containing nitrogen, was digested according to Kjeldahl's method and the evolved ammonia was absorbed in 20mL of 0.1MHCl solution. The excess of the acid solution for complete neutralisation. The percentage of nitrogen in the compound is
- (a)
59.0
- (b)
47.4
- (c)
23.7
- (d)
29.5
The compound formed in the positive test for nitrogen with the Lassaigne solution of an organic compound is
- (a)
Fe(CN)3
- (b)
Fe4[Fe(CN)6]3
- (c)
Na4[Fe(CN)5NOS]
- (d)
Na3[Fe(CN)6]