Jamb Chemistry 2018 Past Questions and Answers

Question 41:

• JAMB 2018

A balanced chemical equation obeys the law of

A. Conservation of mass
B. Definite proportions
C. Multiple proportions
D. Conservation of energy

Question 42:

• JAMB 2018

When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are;

A. Nitrogen and carbondioxide
B. The rare gases
C. Nitrogen and oxygen
D. Nitrogen and the rare gases

Question 43:

• JAMB 2018

In the laboratory preparation of oxygen, the gas cannot be collected by displacement of air because

A. The density of oxygen is greater than that of air
B. The density of air is nearly the same as that of oxygen
C. Oxygen is a component of air
D. Air is an impure substance

Question 44:

• JAMB 2018

2KClO3(g) MNO3→ 2KCl(s) + 3O2(g)
The importance of the catalyst in the reaction above is that

A. Heating may not be required before the reaction takes place
B. The reaction is controllable even at a high temperature
C. The reaction produces large quantity of oxygen
D. The reaction takes place more rapidly at a lower temperature

Question 45:

• JAMB 2018

Which of the following is used to power steam engines?

A. Lubricating oil
B. Coal
C. Bitumen
D. Diesel oil