Chemistry 2018 Jamb Past Questions and Answers

Question 71 :

• JAMB 2018

During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment

A. The litmus turns blue but no gas is evolved
B. The litmus turns blue and oxygen is evolved
C. The litmus turns blue and hydrogen is evolved
D. The litmus turns red and oxygen is evolved

Question 72 :

• JAMB 2018

The derivative of benzene that can be used in making explosives is

A. Aniline
B. Xylene
C. Phenol
D. Toluene

Question 73 :

• JAMB 2018

In electrovalency, the oxidation number of the participating metal is always

A. Decreasing
B. Increasing
C. Constant
D. Neutral

Question 74 :

• JAMB 2018

The ionic radii of metals are usually

A. Greater than their atomic radii
B. Unaffected by the charge on the ion
C. The same as their atomic radii
D. Less than their atomic radii

Question 75 :

• JAMB 2018

Calculate the percentage composition of oxygen in calcium trioxocarbonate(IV) [Ca=40, C=12, O=16]

A. 16
B. 48
C. 40
D. 12