Separation of mixtures and purification of chemical substances - Jamb Chemistry Past Questions and Answers

Question 71:

• JAMB 2008

Chlorophyll obtained from given leaves of plant can be shown to be composed of more than one coloured component by the technique of

A. Crystallization
B. Hydrolysis
C. Chromatography
D. Sublimation

Question 72:

• JAMB 2008

In countries where the temperature falls below 273K, salt is always sprinkled on the icy road in order to

A. Lower the melting point of the ice
B. Increase the density of the ice
C. Make the ice impure
D. Raise the melting point of the ice

Question 73:

• JAMB 2008

Leads is used for making bullets and lead shots because of its

A. Resistance to corrosion
B. Low melting point
C. High density
D. Flexibility

Question 74:

• JAMB 2008

which of the following gives a precipitate when treated with NaOH solution?

A. AlCl₃
B. NH₄Cl
C. Na₂CO₃
D. CH₃COONa

Question 75:

• JAMB 2009

A mixture of sugar and sulphur can be separated by

A. Dissolution in water, evapouration and filtration
B. Filtration, evaporation and dissolution in water
C. Dissolution in water, filtration and evaporation
D. Evaporation, dissolution in water and filtration