Waec Chemistry 1991 Past Questions and Answers

Question 26:

• WAEC 1991

How many principal electronic shells has an atom whose electronic configuration is shown below? 1s²2s²2p⁶3s¹

A. 1
B. 2
C. 3
D. 4
E. 11

Question 27:

• WAEC 1991

Which of the following properties is not characteristic of electrovalent compounds?

A. Formation of crystalline solids
B. Solubility in polar solvents
C. High vapour pressures
D. High melting and boiling points
E. Ability to conduct electricity in aqueous solution

Question 28:

• WAEC 1991

Compounds that have the same molecular formula but different structures are said to be

A. Allotropic
B. Polymorphic
C. Polymeric
D. Isomeric
E. Isotopic

Question 29:

• WAEC 1991

In which of the following crystals are the particles held by van der Waal's forces only?

A. Sodium chloride
B. Ice
C. Diamond
D. Iodine
E. Quartz

Question 30:

• WAEC 1991

A current of 4.0 amperes was passed through copper (ll) tetraoxosulphate (IV) solution for one hour using copper electrodes. What was the mass of copper deposited? (Cu = 64, 1F = 96500 C)

A. 3.2g
B. 4.8g
C. 6.4g
D. 48g
E. 96g