Chemistry and Industry - Jamb Chemistry Past Questions and Answers

Question 36:

• JAMB 1988

When H₂S gas is passed into a solution of iron (III) chloride, the colour changes from yellow to green. This is because?

A. H_(s)S is reduced to S
B. Fe³⁺ ions are oxidized by H_(s)S
C. Fe³⁺ ions are oxidized Fe³⁺ ions
D. Fe³⁺ ions are reduced to Fe²⁺ ions

Question 37:

• JAMB 1988

Suitable reagents for the laboratory preparation nitrogen are?

A. Sodium dioxonitrate (III) and ammonium chloride
B. Sodium dioxonitrate (V) and ammonium chloride
C. Sodium chloride and ammonium chloride
D. Sodium chloride and ammonium diozonitrate (III)

Question 38:

• JAMB 1988

The thermal decomposition of copper (ll)trioxonitrate (V) yields copper (ll) oxide, oxygen and?

A. Nitrogen (ll) oxide
B. Nitrogen (l) oxide
C. Nitrogen (lV) oxide
D. Nitrogen

Question 39:

• JAMB 1988

Chlorine is produced commmercially by?

A. Electrolysis of dilute hydrochloric acid
B. Electrolysis of brine
C. Neutralization of hydrogen chloride
D. Heating potassium trioxochlorate (V)

Question 40:

• JAMB 1988

Aluminium is extracted commercially from its ore by?

A. Heating aluminium oxide with coke in a furance
B. The electrolysis of fused aluminium oxide in cryolite
C. Treating cryolite with sodium hydroxide solution under prressure
D. Heating sodium aluminium silicate to a high temperature