Identifying the Products of Chemical Reactions (OCR GCSE Combined Science A (Gateway): Chemistry): Exam Questions

Exam code: J250

16 mins9 questions
1
1 mark

Damp litmus paper is used to test for chlorine gas.

Which statement describes the correct result of the test for chlorine gas?

  • Damp blue litmus paper turns red then white.

  • Damp blue litmus paper turns white then red.

  • Damp red litmus paper turns blue then white.

  • Damp red litmus paper turns white then blue.

2
1 mark

What is the test for chlorine gas?

  • Damp universal indicator paper turns red then white

  • Decolourises bromine water

  • Limewater turns milky

  • Relights a glowing splint

1
1 mark

During the electrolysis of brine, chlorine gas forms at one electrode.

2Cl- (aq) rightwards arrowCl2 (g) + 2e-

Which test would be most appropriate to confirm that chlorine gas was produced?

  • Collect the gas and see if it extinguishes a glowing splint

  • Collect the gas and check if it is green

  • Collect the gas and see if it bleaches damp litmus paper

  • Collect the gas and check if it smells of swimming pools

2
1 mark

Which is the correct method for testing for hydrogen gas?

  • Hold the tube containing the gas upright and place a lit splint at the end of the tube

  • Hold the tube containing the gas upright and place a glowing splint at the end of the tube

  • Hold the tube containing the gas angled down and place a lit splint at the end of the tube

  • Hold the tube containing the gas angled down and place a glowing splint at the end of the tube

3
1 mark

Which is not true about the test for carbon dioxide gas?

  • The gas is bubbled through limewater solution

  • Limewater is calcium hydroxide solution

  • The solution will turn cloudy due to the formation of a white precipitate

  • The colour will fade after a few minutes

4
1 mark

What is the correct observation when a glowing splint is held at the entrance of a tube of pure oxygen gas? 

  • A 'squeaky pop' sound can be heard

  • The glowing splint relights

  • The glowing splint keeps glowing

  • The glowing splint is immediately extinguished

5
1 mark

The electrolysis of fresh water produces hydrogen gas and oxygen gas.

The electrolysis of salt water (brine) produces hydrogen gas and chlorine, and leaves a solution of sodium hydroxide.

Which test would not help to identify a sample as being fresh water or salt water?

  • A gas collected makes a 'squeaky pop' when a lit splint is held in it

  • A gas collected relights a glowing splint

  • A gas collected bleaches damp litmus paper

  • The pH of the solution increases

6
1 mark

Which statement describes the test for chlorine gas?

  • A lighted splint makes a squeaky pop.

  • Limewater turns milky.

  • A glowing splint re-lights.

  • Damp litmus paper is bleached.