Air - Jamb Chemistry Past Questions and Answers

Question 6:

• JAMB 1981

When air is compressed?

A. Its density decreases
B. It solidifies
C. Its temperature decreases
D. Its temperature increases
E. Its temperature remains unchanged

Question 7:

• JAMB 1982

When air is passed through alkaline pyrogallol and then over quicklime, the only gases left are?

A. Nitrogen and carbondoxide
B. The rare gases
C. Nitrogen and oxygen
D. Nitrogen and the rare gases
E. Nitrogen, carbonioxide and the rare gases

Question 8:

• JAMB 1990

Which of the following gases can be collected by the upward displacement of air?

A. NO
B. H ₂
C. NH₃
D. Cl ₂

Question 9:

• JAMB 1990

10.0 dm³ of air containing H₂S as an impurity was passed through a solution of Pb(NO₃)₂ until all the H₂S had reacted. The precipitate of PbS was found to weigh 5.02 g. According to the equation:
Pb(NO₃)₂ + H₂S → PbS + 2HNO₃ the percentage by volume of hydrogen sulphide in the air is?
(Pb = 207, S = 32, GMV at s.t.p = 22.4dm³)

A. 50.2
B. 47.0
C. 4.70
D. 0.47

Question 10:

• JAMB 1990

Smoke consist of?

A. Solid particles dispersed in liquid
B. Solid or liquid particles dispersed in gas
C. Gas or liquid particles dispersed inliquid
D. Liquid particles dispersed inliquid