Question 21:

• JAMB 1978

The statements below were made by some students describing what happened during the determination of the melting point of solids.
i. the temperature of the solid was solid until melting started
ii. the temperature of the solid rose until melting started
iii. during melting, the temperature was rising
iv. during melting, the temperature was constant
v. the temperature continued to rise after all the solid had melted
vi. the temperature stopped rising after all the solid had melted. Which of the following gives correct statements in the right order?

A. Ii, iv, and v
B. Ii, iii and vi
C. I, iii and vi
D. I, iii and v
E. I, iv and v

Question 22:

• JAMB 1978

A few grains of table salt were put in a cup of water, kept at constant temperature and left undisturbed. Eventually all the water tasted salty. The action is due to

A. Convection
B. Osmosis
C. Capillarity
D. Diffusion
E. Conductivity

Question 23:

• JAMB 1978

A temperature 20°C is the same as

A. 36^oF
B. 68^oF
C. 11.1^oF
D. 43.1^oF
E. 25^oF

Question 24:

• JAMB 1978

The latent heat of fusion of ice is 80cal g^-1. How much heat is required to change 10g of ice at Q^oC into water at the same temperature?

A. 80 cal
B. 10 cal
C. 8 cal
D. 800 cal
E. 400 cal

Question 25:

• JAMB 1978

A gas at pressure PNm\(^{-2}\) and temperature 27°C is heated to 77°C at constant volume. The new pressure is

A. 0.85 PN-m^-2
B. 0.86 PN-m^-2
C. 1.16 PN-m^-2
D. 1.18 PN-m^-2
E. 2.85 PN-m^-2