Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
States of Matter
102 practice questions
Topics covered
Practice questions
31–40 of 42 · Easy
Question 31
2 marks · Easy
Answer and see the solution →A student found that 25.8 g of sodium chloride was obtained after evaporating all the water from a saturated solution made with 75 g of water at a certain temperature.
Calculate the solubility of sodium chloride in g per 100 g water at that temperature. Show your working.
Question 32
1 mark · Easy
Answer and see the solution →State the equation used to calculate the solubility (in g per 100 g of water) from the mass of solute and mass of solvent.
Question 33
3 marks · Easy
Answer and see the solution →The table below shows the solubility of calcium nitrate at various temperatures.
Solubility of calcium nitrate at different temperatures Temperature /°C Solubility /g per 100 g water 10 129 30 136 50 145 70 151 90 156 (a)[2 marks]Draw a labelled solubility curve for calcium nitrate using the data.
(b)[1 mark]State the dependent variable on the graph.
Question 34
2 marks · Easy
Answer and see the solution →Use the solubility curve for potassium bromide (KBr) below to determine the solubility at 60°C.
Incomplete solubility curve for potassium bromide Question 35
2 marks · Easy
Answer and see the solution →Explain, using a solubility curve, how you would determine how much solid potassium sulfate would crystallise from a saturated solution as it cools from 70°C to 30°C.
Question 36
3 marks · Easy
Answer and see the solution →A student performed an experiment to measure the solubility of sodium nitrate. Her results are:
Experimental data for sodium nitrate solubility Mass of evaporating dish (g) Mass of dish + solution (g) Mass of dish + dry sodium nitrate (g) 22.00 60.00 32.50 (a)[1 mark]Calculate the mass of sodium nitrate dissolved in the solution.
(b)[1 mark]Calculate the mass of water in the solution.
(c)[1 mark]Calculate the solubility of sodium nitrate in g per 100 g of water.
Question 37
1 mark · Easy
Answer and see the solution →When plotting a solubility curve, on which axis should you put temperature?
Question 38
3 marks · Easy
Answer and see the solution →The solubility curve for barium chloride shows that its solubility is 37 g per 100 g water at 60°C, and 29 g per 100 g water at 30°C.
(a)[2 marks]How many grams of barium chloride will dissolve in 40 g of water at 60°C?
(b)[1 mark]What is the maximum temperature at which 10 g of barium chloride will just dissolve in 20 g of water?
Question 39
2 marks · Easy
Answer and see the solution →A solution contains 52 g of potassium iodide dissolved in 100 g of water at 60°C. The solubility curve for potassium iodide shows a solubility of 70 g per 100 g water at 60°C and 40 g per 100 g water at 30°C. Calculate the mass of potassium iodide that will crystallise out if the solution is cooled from 60°C to 30°C.
Question 40
5 marks · Easy
Answer and see the solution →A scientist describes placing solid iodine in an open dish in a laboratory. After a few hours, no solid remains, and a purple vapour fills the dish.
(a)[1 mark]Describe the arrangement and movement of particles in solid iodine at room temperature.
(b)[1 mark]Identify the name of the process that causes solid iodine to disappear and form a vapour.
(c)[2 marks]Explain, using particle theory, what happens to the particles of iodine during this process.
(d)[1 mark]State one difference between the arrangement of particles in the iodine vapour and in the solid.