Chemistry 1997 Jamb Past Questions and Answers

Question 11 :

• JAMB 1997

If 30cm³ of oxygen diffuses through porous plug in 7s, how long will it take 60 cm³ of chlorine to diffuse through the same plug?

A. 12s
B. 14s
C. 21s
D. 30s

Question 12 :

• JAMB 1997

200 cm³ of air was passed over heated copper in a syringe several times to produce copper (II) oxide.
When cooled, the final volume of air recorded was 158cm³. Estimate the percentage of oxygen in the air?

A. 31%
B. 27%
C. 21%
D. 19%

Question 13 :

• JAMB 1997

On recrystallization, 20g of magnesium tetraoxosuphate (IV) forms 41 g of magnesium tetraoxosulphate (IV) crystals, MgSO₄. yH₂O. The value of y is?
(Mg = 24, S = 32, O = 16, H = 1)

A. 1
B. 3
C. 5
D. 7

Question 14 :

• JAMB 1997

Which of the following gases is the most dangerous pollutant?

A. Hydrogen sulphide
B. Carbon (lV) oxide
C. Sulphur (lV) oxide
D. Carbon (ll) oxide

Question 15 :

• JAMB 1997

A major process involved in the softening of hard water is the?

A. Conversation of a soluble calcium salt to its trioxoncarbonate (lV)
B. Decomposition of calcium rioxocarbonate (lV)
C. Conversion of an insoluble calcium salts to its trioxocarbonate (lV)
D. Oxidation of calcium atoms to its ions