Waec Chemistry 2006 Past Questions and Answers

Question 16:

• WAEC 2006

The oxidation number of iodine in the iodate ion (IO ^-₃) is

A. -5
B. -1
C. +1
D. +5

Question 17:

• WAEC 2006

Metals can be extracted from their ores by a process involving

A. Reduction
B. Oxidation
C. Hydrolysis
D. Decomposition

Question 18:

• WAEC 2006

Consider the reaction: 2AI_(s) + 6H⁺_(aq) → 2AI³⁺_(aq) + 3H_2(g). What is the total number of moles of electrons transferred from the aluminium atoms to the hydrogen ions?

A. 3
B. 4
C. 5
D. 6

Question 19:

• WAEC 2006

In the reaction represented by the equation. 5Fe ²⁺_(aq) + MnO^-_4(aq) + 8H⁺_(aq) → 5Fe³⁺_(aq) + Mn^{2+_(aq) + 4H₂O_(l) which species is reduced?}


A. Fe²⁺
B. MnO^-4
C. H⁺
D. Fe³⁺

Question 20:

• WAEC 2006

Which of the following industrial processes is chlorines not used?

A. Production of polyvinylchloride (PVC)
B. Manufacturing of hydrochloric acid
C. Manufacturing of common salt
D. Manufacturing of domestic bleach