Change of State - Jamb Physics Past Questions and Answers

Question 31:

• JAMB 2000

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 32:

• JAMB 2004

When left in a freezer, a bottle full of water cracks on freezing into ice because of the

A. Increase in the volume of water
B. Contraction of the bottle
C. Expansion of the bottle
D. Decrease in the volume of water

Question 33:

• JAMB 2005

10⁶J of heat is required to boil off completely 2kg of a certain liquid. Neglecting heat lost to the surroundings, the latent heat of vaporization of the liquid is

A. 2.0 x 10⁶J kg^-1
B. 5.0 x 10⁶J kg^-1
C. 2.0 x 10⁵J kg^-1
D. 5.0 x 10⁵J kg^-1

Question 34:

• JAMB 2008

When cold water is poured on a can containing hot water, the can collapses because the

A. Steam condeses and occupies the partial vacuum in the can
B. External air pressure counter balances the pressure within the can
C. Steam expands to occupy the vacuum remaining in the can
D. External pressure becomes greater than the pressure within the can.

Question 35:

• JAMB 2008

The diagram above is the heating curve for a solid QR is the

A. Melting region
B. Boiling region
C. Sublimation region
D. Evaporating process