Waec Chemistry 2004 Past Questions and Answers

Question 31:

• WAEC 2004

Consider the cell represented below: Zn/Zn²⁺_(aq) // Cu²⁺_(aq) / Cu_(s). Which of the following statements is correct about the cell

A. Zn is oxidized to Zn²⁺
B. Cu is oxidized to Cu²⁺
C. It is an electrolytic cell
D. Each single line represents a salt bridge

Question 32:

• WAEC 2004

When ammonium trioxocarbonate (IV) solution is added to separate solutions of calcium, zinc and sodium salt precipitate could be formed in the case of

A. Calcium only
B. Zinc only
C. Calcium and znic only
D. Sodium and zinc only

Question 33:

• WAEC 2004

The condensation of several amino acid molecules gives

A. Long chain alkanoic acids
B. Secondary alkanols
C. Alkanoates
D. Proteins

Question 34:

• WAEC 2004

Which of the following statements is true of an endothermic reaction? I. Heat is absorbed from the surrounding II. The heat content of the products is more than that of the reactants III. The enthalpy change is positive IV. The surrounding is at a lower temperature than the system.

A. L only
B. L and ll only
C. L,ll and lll only
D. L, ll, lll and lV

Question 35:

• WAEC 2004

What is the change in the oxidation number of 1^- in the reaction represented by the following equation? 51 ^-1_(aq) + 6H⁺_(aq) + 1O^-_3(aq) → 31_2(g) + 3H₂O_(l)

A. -5 to -3
B. -1 to 0
C. + 5 to + 0
D. -1 to + 2