7h Solutions Test 2004

Do not write on this sheet! For questions 1 to 8 choose the correct word from the brackets to make each sentence correct

Substance

1. Salt dissolves in water so the mixture is (soluble/clear/insoluble) after shaking. 2. We say salt is (soluble/clear/insoluble) in water. Water 3. Sand does not dissolve in water. We say it is (soluble/clear/insoluble). 4. A liquid that can dissolve another substance is called a (solvent/solution/solute). Substance Shake 5. A substance that can dissolve in a liquid is called a (filtrate/solvent/solution/solute). 6. The warmer a cup of tea is, the more sugar will be able to dissolve in it. We say that the warmer the tea, the greater the (speed/solubility/saturation) of the sugar. 7. If no more sugar can be dissolved in a cup of water, then the solution is said to be (soluble/full/residue/saturated) 8. If a mixture of chalk and water is filtered using a filter paper and funnel, the clear water that passes through the paper is known as the (residue/solute/filtrate). 9. If 30 grams of salt are dissolved into 120 grams of water to make a salt solution, how much will the salt solution weigh (in grams)? 10. Without using the word "dissolved" in your answer, describe what has happened to the salt particles in question 9. 11.

12.

13.

Water is not a solvent for grease. This means that grease is ….. A insoluble in water B soluble in water C insoluble in anything except water D insoluble in any liquid Which statement is wrong? A sugar is soluble in water C sugar is the solute in a sugar solution

B sugar dissolves in water D sugar melts in water

The box contains the names of substances you find in the kitchen. Choose the three which are soluble in water. sugar salt jelly rice flour tea leaves .

Complete the sentences to answer questions 14 to 17 using words from the box distillationchromatography 14. 15. 16. 17.

evaporation

filtration

.

To separate the colours in ink we use a process called ____________ . To get clear water from salt solution we use a process called ___________ . To get clear water from muddy water we use a process called ______________. To get salt crystals from salt solution we use a process called ___________.

Clear

18. Put the following sentences in order to describe how you would get pure salt from rock salt (a mixture of salt and sand). A We would add hot water to the mixture and stir with a stirring rod. B We would crush up the rock salt with a mortar and pestle. C We would gently warm the filtrate in an evaporating basin. D We would carefully filter the mixture using a funnel and filter paper. 19. Which one of the following (A, B, C, or D) describes the process of distillation? A evaporation followed by condensation B condensation followed by evaporation C evaporation followed by crystallisation D condensation followed by boiling This diagram shows the results of a chromatography experiment to identify an unknown ink mixture. 20. What would be a suitable solvent for this experiment? 21. Why do the inks move upwards? 22. Which of inks 1,2,3 and 4 is the ink mixture made up from?

The diagram shows some apparatus used for the distillation of inky water. 23. Which label on the diagram shows where the inky water is? (A, B, C, D or E)? 24. Which label shows where there is pure water? 25. Which label shows where condensation is happening? 26. Describe what there is in the round bottom flask at position B. A pupil measures how much sugar will dissolve in water at different temperatures. These are her results. Temperature (oC)

0

20

40

60

80

Amount of sugar that will dissolve (g)

14

20

29

40

56

27. 28. 29. 30.

At which temperature did the most sugar dissolve? Describe one thing the pupil must have done to ensure this was a fair test. What could the pupil do to be sure these results were reliable? Describe the relationship between the temperature of the water and the amount of sugar that will dissolve.

Now go back and check your work to make sure you haven’t made any silly mistakes.