Change of State - Jamb Physics Past Questions and Answers

Question 41:

• JAMB 2012

I. A liquid boils when its saturated vapour pressure is equal to the external pressure
II. Dissolved substances in pure water lead to increase in the boiling point.
III. When the external pressure is increased, the boiling point increases.
IV. Dissolved substances in pure water decrease the boiling point.
Which combination of the above are peculiarities of the boiling point of a liquid?

A. I, II and III
B. I, II, III and IV
C. I, II and IV
D. II, III and IV

Question 42:

• JAMB 2012

A thin wire with heavy weights attached to both ends is hung over a block of ice resting on two supports. If the wire cuts through the ice block while the block remains solid behind the wire, the process is called

A. Condensation
B. Sublimation
C. Regelation
D. Fusion

Question 43:

• JAMB 2013

Steam from boiling water causes more damage on the skin than does boiling water because

A. Water has a high specific heat
B. Steam has latent heat of fusion
C. The steam is at a highter temperature than the water
D. Steam brings heat more easily by convection

Question 44:

• JAMB 2013

What will happen to the boiling point of pure water when it is heated in a place 30m below sea level?

A. It will be more than 100 ^oC
B. It will be last than 100 ^oC
C. It will still be at 100 ^oC
D. It will be fluctuating

Question 45:

• JAMB 2014

The melting point of a substance is equivalent to its

A. Vapour Pressure
B. Solidification Temperature
C. Liquidification Temperature
D. Solidification Pressures