Chemistry 2018 Waec Past Questions and Answers

Question 36 :

• WAEC 2018

The empirical formula of a compound containing 0.067mol Cu and 0.066mol O is [Cu = 63.5, O = 16]

A. \(Cu_{2}O\)
B. \(CuO\)
C. \(CuO_{2}\)
D. \(CuO_{4}\)

Question 37 :

• WAEC 2018

The change in the oxidation state of iron in the reaction represented by the equation: \(2FeCl_{3} + H_{2}S \to 2FeCl_{2} + 2HCl + S\) is

A. +2 to +3
B. 0 to +2
C. +3 to +2
D. +3 to 0

Question 38 :

• WAEC 2018

Which of the following methods can be used to seperate blood cells from plasma?

A. Centrifugation
B. Filtration
C. Chromatography
D. Distillation

Question 39 :

• WAEC 2018

Which of the following statements is true about ionic radius? Ionic radius

A. Increases as nuclear charge increases
B. Decreases as nuclear charge increases
C. Decreases as nuclear charge decreases
D. Remains constant as nuclear charge increases

Question 40 :

• WAEC 2018

Analysis of a hydrocarbon shows that it contains 0.93g of Carbon per gram of the compound. The mole ratio of carbon to hydrogen in the compound is [H = 1.0, C=12.0]

A. 1:1
B. 1:2
C. 2:1
D. 2:3