Question 36:

• JAMB 2019

If hydrogen sulphide gas is passed into a solution of a pure iron chloride, a yellow deposit appears. If the deposit is filtered, a pale green solution is left behind. The pale green solution is

A. Dilute sulphuric acid
B. Dilute hydrochloric acid
C. Unreacted hydrogen sulphide in water
D. Iron (III) chloride
E. Iron (II) chloride

Question 37:

• JAMB 2019

Which of the following changes is physical?

A. Adding iron filing to aerated water
B. Adding sodium metal to water
C. Cooling a solution of Iron (II) sulphate to obtain the hydrated salt
D. Cooling water to obtain ice
E. Burning the domestic gas (Utilgas) for cooking

Question 38:

• JAMB 2019

By means of filtration, one component can be obtained pure from an aqueous mixture of sodium chloride and

A. Potassium nitrate
B. Sand
C. Lead nitrate
D. Sugar (glucose)
E. Starch

Question 39:

• JAMB 2019

In titration involving sodium hydroxide and dilute hydrochloric acid, where would you place the base?

A. In the beaker
B. In the conical flask
C. In a burette
D. In the standard flask
E. In the measuring cylinder

Question 40:

• JAMB 2019

A gas jar was inverted over burning yellow phosphorus floating over water in a beaker. After burning, the water level was found to rise in the gas jar. The water level rises because

A. Pressure inside the gas jar is greater than pressure outside it
B. The air in the gas jar had been used up by burning
C. Oxygen in the gas jar had been used up by burning
D. Nitrogen in the gas jar had been used up by burning
E. The temperature in the jar had risen considerably