Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
States of Matter
102 practice questions
Topics covered
Practice questions
21–30 of 42 · Easy
Question 21
3 marks · Easy
Answer and see the solution →The table shows how long different gases took to diffuse through air in a set apparatus during an experiment.
Time taken for diffusion of different gases through air. Gas Time to mix fully (seconds) Hydrogen 40 Oxygen 60 Ammonia 35 Carbon dioxide 70 (a)[1 mark]Which gas diffused the fastest?
(b)[1 mark]Which gas diffused the slowest?
(c)[1 mark]Suggest, using particle ideas, why there is a difference in the speed at which these gases diffuse.
Question 22
1 mark · Easy
Answer and see the solution →What do you call the uneven spread of particles before diffusion is complete?
Question 23
3 marks · Easy
Answer and see the solution →Two gases, X and Y, are released at opposite ends of a glass tube. After a short time, a white ring forms closer to the end where gas Y was released.
(a)[1 mark]Which gas, X or Y, diffused faster?
(b)[2 marks]Explain why the white ring appears closer to the Y end.
Question 24
2 marks · Easy
Answer and see the solution →A small bottle of perfume breaks at one end of a corridor 18 metres long. If perfume particles travel randomly at an average speed of 600 m/s, calculate:
(a)[1 mark]The time it would take a perfume particle to reach the other end in a straight line, in seconds.
(b)[1 mark]Explain why the actual time to smell the perfume at the other end is much longer.
Question 25
1 mark · Easy
Answer and see the solution →Name one piece of laboratory equipment that can be used to remove undissolved solid from a saturated solution during a solubility experiment.
Question 26
3 marks · Easy
Answer and see the solution →State what is meant by the following terms.
(a)[1 mark]solvent
(b)[1 mark]solution
(c)[1 mark]saturated solution
Question 27
2 marks · Easy
Answer and see the solution →At 25°C, the solubility of potassium nitrate is 38 g per 100 g of water. Calculate the maximum mass of potassium nitrate that will dissolve in 250 g of water at this temperature. Show your working.
Question 28
2 marks · Easy
Answer and see the solution →Explain why it is important to heat the evaporating basin until its mass remains constant when measuring the solubility of a salt.
Question 29
1 mark · Easy
Answer and see the solution →State what is meant by a solution in chemistry.
Question 30
3 marks · Easy
Answer and see the solution →(a)The diagram below shows a solubility curve for a salt.
Solubility curve for salt W. (i)[1 mark]State the solubility of salt W at 20°C.
(ii)[1 mark]Describe what happens to the solubility of salt W as the temperature increases from 0°C to 60°C.
(iii)[1 mark]Explain, with reference to the solubility curve, how to tell when a solution of salt W at 40°C is saturated.