Engineering Chemistry Multiple Choice Questions on “Column Chromatography”.
1. Column chromatography is based on the principle of _______________
a) Ion-exchange
b) Exclusion principle
c) Differential adsorption
d) Absorption
Answer: c
Clarification: Column chromatography is based on the principle of differential adsorption. It means different compounds have different tendencies to get adsorb on a particular surface.
2. Arrange the following compounds in order of their increasing adsorption tendencies.
a) Cellulose >> starch >> calcium carbonate >> alumina
b) Cellulose >> starch >> alumina >> charcoal
c) Charcoal >> cellulose >> alumina >> starch
d) Calcium carbonate >>; alumina >> starch >> cellulose
Answer: a
Clarification: Cellulose >> starch >> calcium carbonate >> charcoal >> alumina is the correct order of increasing adsorption tendencies.
3. What is the factor responsible for the separation in column chromatography?
a) Polarity differences between the solvent
b) Polarity differences between the solute
c) Polarity indifference between the solvent
d) Polarity indifference between the solute
Answer: b
Clarification: Polarity differences between the solute molecules are responsible for the separation in column chromatography.
4. Select the correct statement from the following options.
a) The lesser the polarity of solute, more strongly it will be adsorbed on a polar surface
b) The greater the polarity of solute, more weakly it will be adsorbed on a polar surface
c) The greater the polarity of solute, more strongly it will be adsorbed on a polar surface
d) All of the mentioned option
Answer: c
Clarification: The greater the polarity of solute, more strongly it will be adsorbed on a polar surface.
5. The correct order of increasing strength of adsorption is ____________
a) Alkanes >> Esters >> Aldehydes >> Phenols >> Ketones
b) Aldehydes >> Phenols >> Ketones >> Esters >> Alkanes
c) Aldehydes >> Ketones >> Esters >> Alkanes >> Phenols
d) Alkanes >> Esters >> Ketones >> Aldehydes >> Phenols
Answer: d
Clarification: the correct order increasing strength of adsorption is: Alkanes >> Esters >> Ketones >> Aldehydes >> Phenols.
6. The components of the mixture in column chromatography are eluted in order of ____________
a) Increasing polarity and decreasing distribution ratio
b) Increasing polarity and increasing distribution ratio
c) Decreasing polarity and increasing distribution ratio
d) Decreasing polarity and decreasing distribution ratio
Answer: b
Clarification: The components of the mixture in column chromatography are eluted in order of increasing polarity and increasing distribution ratio.
7. The elution power of a solvent is determined by ____________
a) Its overall polarity
b) The polarity of the stationary phase
c) The nature of the sample components
d) All of the mentioned
Answer: d
Clarification: The elution power of a solvent is determined by its overall polarity, the polarity of the stationary phase and the nature of the sample components.
8. Which of the following is separated through column chromatography?
a) Chlorophyll and carotenoids
b) Inorganic cations or complexes
c) Sugar derivatives
d) Amino acids formed by hydrolysis of a protein molecule
Answer: a
Clarification: The main application of column chromatography is to separate plant pigment (Chlorophyll and carotenoids).
9. The mixture of petroleum ether and benzene is used in the elution ratio of ____________
a) 1 : 2
b) 1 : 5
c) 1 : 9
d) 1 : 12
Answer: c
Clarification: The mixture of petroleum ether and benzene is used in the elution ratio of 1:9 (V/V).
10. Chloroform fraction is eluted from the column by passing chloroform through the column which acts as ____________
a) Eluter
b) Eluant
c) Elution
d) None of the mentioned option
Answer: c
Clarification: Chloroform fraction is eluted from the column by passing chloroform through the column which acts as eluant. The eluate is the mobile phase leaving the column. The eluent is the solvent that carries the analyte.