Jamb Chemistry 1994 Past Questions and Answers

Question 1:

• JAMB 1994

A mixture of sand, ammonium chloride and sodium chloride is best separated by?

A. Sublimation followed by addition of water and filteration
B. Sublimation followed by addition of water and evaporation
C. Addition of water followed by filtration and sublimation
D. Addition of water followed by crystallization and sublimation

Question 2:

• JAMB 1994

A pure solid usually melts?

A. Over a wide range of temperature
B. Over a narrow range of temperature
C. At a lower temperature than the impure one
D. At the same temperature as the impure one

Question 3:

• JAMB 1994

At the same temperature and pressure, 50 cm³ of nitrogen gas contains the same number of molecules as?

A. 25 cm³ of methane
B. 40 cm³ of hydrogen
C. 50 cm³ of ammonia
D. 100 cm³ of chlorine

Question 4:

• JAMB 1994

8g CH₄ occupies 11.2 dm³ at s.t.p. What volume would 22 g of CH₃CH₃ occupy under the same condition?
(C = 12, H = 1)

A. 3.7 dm³
B. 11.2 dm³
C. 22.4 dm³
D. 33.6 dm³

Question 5:

• JAMB 1994

To what temperature must a gas 273 K be heated in order to double both its volume and pressure?

A. 298 K
B. 546 K
C. 819 K
D. 1092 K