Chemistry 2003 Waec Past Questions and Answers

Question 16 :

• WAEC 2003

Which of the following statements about an exothermic reaction is correct?

A. The products have less heat content than reactants
B. The system absorbs heat from the surrounding
C. The activation energy is high
D. The enthalpy change is positive

Question 17 :

• WAEC 2003

A reducing agent is expected to

A. Decolourize acidified KMnO₄ solution
B. Decolourize acidified FeSO₄ solution
C. Liberate CI₂ from a chloride
D. Liberate CO₂ from NaHCO₃

Question 18 :

• WAEC 2003

Consider the electrochemical cell represented below Zn_(s)/Zn²⁺_(aq)//Cu²⁺_(aq)/Cu_(s). Which of the following equations describes the reaction occurring in the cell?

A. Cu_(s) + Zn²⁺_(aq) →Cu²⁺_(aq) + Zn_(s)
B. Cu_(s) + Zn_(s) →Cu²⁺_(aq) + Zn²⁺_(aq)
C. Zn_(s) + Cu²⁺_(aq) →Zn²⁺_(aq) + Cu_(s)
D. Zn²⁺_(aq) +Cu²⁺_(aq) → Zn_(s) + Cu_(s)

Question 19 :

• WAEC 2003

Five metals represented by the letters V to Z are arranged in order of their reactivity as shown . V>W>X>Y>Z.
Which of the metals cannot displace Y from an aqueous solution of its salt?

A. V
B. W
C. X
D. Z

Question 20 :

• WAEC 2003

Five metals represented by the letters V to Z are arranged in order of their reactivity as shown . V>W>X>Y>Z.
Which of the metals is most likely extracted by the electrolysis of its fused chloride?

A. V
B. W
C. X
D. Z