Waec Chemistry Past Questions and Answers

Question 1706:

• WAEC 2021

What is the concentration of a solution which contains 0.28g of potassium hydroxide in 100 cm\(^{3}\) of solution [KOH = 56]

A. 0.01 mol dm\(^{-3}\)
B. 0.05 mol dm\(^{-3}\)
C. 0.10 mol dm\(^{-3}\)
D. 0.50 mol dm\(^{-3}\)

Question 1707:

• WAEC 2021

What is the empirical formula of a hydrocarbon containing 0.160 moles of carbon and 0.640 moles of hydrogen

A. CH\(_{2}\)
B. CH\(_{3}\)
C. CH\(_{4}\)
D. C\(_{2}\)H\(_{4}\)

Question 1708:

• WAEC 2021

Which of the following species has the largest ionic radius

A. S\(^{2-}\)K\(^{+}\)
B. CI\(^{-}\)
C. Ca\(^{2+}\)

Question 1709:

• WAEC 2021

Which of the following statements is correct about ionization energy? It

A. Decreases across the periods
B. Results in the formation of an anion
C. Causes Metalic nuclei to disintegrate
D. Decreases down the group

Question 1710:

• WAEC 2021

Potassium trioxonitrate (V) can be obtained from its solution by ____________

A. Distillation
B. Evapoartion
C. Crystallization
D. Filtration