Chemistry Past Questions and Answers

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:

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:

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:

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:

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