Chemistry 2018 Waec Past Questions and Answers

Question 31 :

• WAEC 2018

One of the criteria for confirming the purity of benzene is to determine its

A. Heat capacity
B. Boiling point
C. Mass
D. Colour

Question 32 :

• WAEC 2018

When chlorine is passed through a sample of water, the pH of the water sample would be

A. < 7
B. > 7
C. = 7

Question 33 :

• WAEC 2018

How many atoms are contained in 0.2moles of nitrogen? \([N_{A} = 6.02 \times 10^{23}]\)

A. \(1.20 \times 10^{23}\)
B. \(2.41 \times 10^{23}\)
C. \(3.62 \times 10^{23}\)
D. \(4.82 \times 10^{23}\)

Question 34 :

• WAEC 2018

The strength of metallic bonds depends on the

A. Charge density of the atoms
B. Ductility of the metal
C. Number of valence electrons
D. Total number of electrons in the atom

Question 35 :

• WAEC 2018

When zinc is added to AgNO\(_{3}\) solution, crystals of silver forms on the zinc surface. This indicates that zinc is

A. Oxidised
B. Reduced
C. Decomposed
D. Dissociated