Chemistry 1993 Jamb Past Questions and Answers

Question 16 :

• JAMB 1993

NH₃ + H₃O⁺
→ NH₄⁺ + H₂O. It may be deduced from the reaction above that?

A. A redox reaction has occurred
B. H₃O⁺ acts as an oxidizing agent
C. H₃O⁺ acts as an acid
D. Water acts as ab acid

Question 17 :

• JAMB 1993

4.0 g of sodium hydroxide in 250 cm³ of solution contains?

A. 0.40 moles per dm³
B. 0.10 moles per dm³
C. 0.04 moles per dm³
D. 0.02 moles per dm³

Question 18 :

• JAMB 1993

During the electrolysis of a salt of a metal M, a current of 0.5 A flows from for 32 minutes 10 seconds and deposits 0.325 g of M, What is the charge of the metal ion?
(M = 65, If = 96,500 C per mole of electron)

A. 1
B. 2
C. 3
D. 4

Question 19 :

• JAMB 1993

Which of the reactions occurs at the anode during the electrolysis of a very dilute aqueous solution of sodium chloride?

A. OH^- - e → OH
B. CIsup>- - e → CI
C. OHsup>- + CIsup>-HCI + O₂
D. Na₊ - esup>- Hg (Na)/(Hg) amalgam

Question 20 :

• JAMB 1993

The oxidation states of chlorine in HOCL, HCLO₃ and HCLO₄ are respectively?

A. -1, +5, and +7
B. -1, -5 and 7
C. +1, +3 and +4
D. +1, +5 and +7