Chemistry Past Questions and Answers

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

Question 42:

You are provided with five gas jars containing SO₂, CO₂, H₂, CO and NO respectively. Select a test from A to E which will identify ANY ONE of the gases completely

A Pass each gas into lime water
B Pass each gas into water and test with litmus paper
C Pass each gas into concentrated sulphuric acid
D Expose each gas to atmospheric air
E Expose each gas to fumes of hydrogen chloride

Question 43:

Which of the following substances would you see as an indicator in the titration of sodium carbonate solution against hydrochloric acid (complete neutralisation)?

A Litmus paper
B Phenolphthalein
C Methyl orange
D Universal indicator
E None of these

Question 44:

Which of the five atoms can be described by the following properties: Relative atomic mass is greater than 30 but less than 40, it has odd atomic number and forms a unipositive ion in solution?

Question 45:

A solid X when heated gives off a brown gas. If X is soluble in excess sodium hydroxide solution but insoluble in excess ammonium hydroxide solution, then X is

A Basic lead carbonate
B Lead (II) nitrate
C Sodium carbonate
D Zinc nitrate
E Sodium nitrate