Boiling and melting points - Jamb Chemistry Past Questions and Answers

Question 11:

• JAMB 2002

A little quantity of trichloromethane (b.pt 60,^oC) was added to a large quantity of ethanol (b.pt 78,^oC). The most probable boiling point of the resultant mixture is from

A. 69 ^oC - 70 ^oC
B. 70 ^oC – 74 ^oC
C. 82 ^oC – 84 ^oC
D. 60 ^oC – 78 ^oC

Question 12:

• JAMB 2007

Which of the following alkanes has the highest boiling point?

A. Pentane
B. Ethane
C. Propane
D. Methane

Question 13:

• 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 14:

• JAMB 2013

The presence of an impurity in substance will cause the melting point to

A. Be zero
B. Reduce
C. Increase
D. Be stable

Question 15:

• JAMB 2018

The boiling of fat and aqueous caustic soda is referred to as

A. Hydrolysis
B. Esterification
C. Acidification
D. Saponification