Jamb Chemistry 1979 Past Questions and Answers

Question 21:

• JAMB 1979

Indicate which of the following statements is not true as we move from left to right along the periodic Table:

A. Atomic number of elements increases
B. Atomic mass of elements increases
C. Electropositive character of elements increases
D. Electronegative character of elements increases
E. Number of electrons in the outermost orbits of element increases

Question 22:

• JAMB 1979

0.1 Faraday of electricity was passed through a solution of copper (ll) sulphate. The maximum weight of copper deposited on the cathode would be [Cu = 64]

A. 64.0g
B. 32.0g
C. 16.0g
D. 6.4 g
E. 3.2g

Question 23:

• JAMB 1979

Which one of these compounds will NOT give an oxygen gas on heating?

A. Manganese dioxide
B. Hydrogen peroxide
C. Zinc nitrate
D. Sodium nitrate
E. Ammonium nitrate

Question 24:

• JAMB 1979

In the extraction of aluminum from purified bauxite by electrolysis, cryolite is used because

A. It makes bauxite a better conductor of electricity
B. It makes bauxite melt at a lower temperature
C. It makes aluminium purer
D. It prevents aluminium from getting oxidized
E. It protects the carbon electrodes used in the process

Question 25:

• JAMB 1979

In the redox reaction 2Fe²⁺ + CI₂ → 2Fe ^{3 +} + 2Cl

A. Cl₂ is reduced because it has lost electrons
B. Cl₂ is reduced because its oxidation number has decreased
C. Cl₂ is reduced because its molecule is change to two ions
D. Fe²⁺ is reduced because it has lost electrons
E. Fe²⁺ is reduced because it has gained electrons