ScienceYear 10

Year 10 Science – Solutions and Mixtures 1

Analyse state-change, density and solubility data, classify matter from particle models, and choose separation methods for tricky mixtures. 20 questions. 25 minutes.

Water from a hot shower ends up as droplets on a cold mirror. Which pair of changes of state happened, in order?

Condensation, then evaporationEvaporation, then condensationBoiling, then freezingSublimation, then melting

A student heats ice and takes a reading at fixed intervals. Choose the word that completes each blank.

The independent variable is ₁ and the dependent variable is ₂.

Blank 1: temperature · mass · time

Blank 2: mass · temperature · volume

Choose the word or phrase that completes each blank.

Oil floats on water, so its density is ₁ 1.0 g/mL. Adding detergent to the water ₂ its surface tension.

Blank 1: less than · greater than · equal to

Blank 2: raises · lowers · does not change

Circle 2 words in the sentence below.

Click the two pure substances in this list.

airbrasswateroxygenseawater

Choose the word or phrase that completes each blank.

Water (H₂O) is a ₁ because its atoms are ₂.

Blank 1: element · mixture · compound

Blank 2: bonded in a fixed ratio · unbonded in any ratio · all one type of atom

Which mixture is best separated by tossing it in a coolamon in the wind?

Seeds mixed with dry husksSugar dissolved in waterIron filings mixed with sandSand mixed with salt

Choose the word or phrase that completes each blank.

Salty water is poured through filter paper. The dissolved particles ₁, so the filtrate is ₂.

Blank 1: pass straight through · are stopped · settle on top

Blank 2: pure water · still salty · a clear solid

Choose the word that completes each blank.

To compare how much of several different solutes dissolve, draw a ₁ graph. To show one solute's solubility at different temperatures, draw a ₂ graph.

Blank 1: pie · scatter · bar

Blank 2: bar · pie · line

Cooking oil sits in a layer on top of water in a jar. A student wants to collect both liquids unchanged. Which method and reason is correct?

Filtration, because the oil droplets are larger than the pores in the paperEvaporation, because the water leaves as vapour while the oil staysSeparating funnel, because the liquids do not mix and differ in densityChromatography, because the oil is more soluble in the solvent than water

10.

A student says: "Salt water is a compound because I cannot see the salt and water separately." Which response is correct?

It is a compound, because the salt is bonded to the water in a fixed ratioIt is an element, because it looks like one uniform substanceIt is a compound, because it can only be split by a chemical changeIt is a mixture, because the salt is not bonded to the water and keeps its properties

11.

Circle 2 words in the sentence below.

Water has a density of 1.0 g/cm³. Four objects have these densities: A 0.85 g/cm³, B 1.20 g/cm³, C 0.99 g/cm³, D 2.7 g/cm³. Click the two objects that float in water.

ABCD

12.

A pure liquid is heated at a steady rate. Which statement best explains the readings from 4 to 8 minutes?

Time (min)	Temperature (°C)
0	25
2	62
4	100
6	100
8	100
10	115

The heater has reached its maximum output, so the temperature cannot riseThe particles have stopped moving, so the temperature stays the sameEnergy is speeding up the particles, but heat escapes to the air so the temperature stays the sameEnergy is breaking attractions between particles, so the temperature stays the same

13.

Choose the word that completes each blank.

To grow large copper sulfate crystals, a hot saturated solution is cooled ₁. The crystals form because solubility ₂ as the solution cools.

Blank 1: quickly · slowly · while stirring hard

Blank 2: falls · rises · stays constant

14.

A tank holds 250 mL of ethanol, which has a density of 0.79 g/mL. What is the mass of the ethanol?

316 g250 g198 g0.32 g

15.

A wooden block has a mass of 500 g and a volume of 800 cm³. A steel ball has a mass of 60 g and a volume of 7.6 cm³. Which statement is correct?

The block floats and the ball sinks, because only the block is less dense than waterThe block sinks and the ball floats, because the block has the greater massBoth sink, because both objects have a mass greater than 1 gBoth float, because the ball's small volume makes it lighter

16.

Circle 1 word in the sentence below.

Solubility in g/100 mL at 20 °C then 60 °C: sugar 204 → 287; potassium nitrate 32 → 110; carbon dioxide 0.17 → 0.07; sodium chloride 36 → 37. Click the solute that does not follow the usual trend for solids.

sugarpotassium nitratecarbon dioxidesodium chloride

17.

A particle diagram shows 6 identical groups, each a dark circle joined to two light circles, plus 4 separate light circles that are not joined to anything. What does the diagram show?

A pure compound with some extra atoms in itA mixture of a compound and an elementA single compound made of two elementsA mixture of two elements

18.

A dam is polluted with soil and dissolved vinegar. Which plan removes both pollutants?

Let the soil settle and decant, then distil the waterFilter the water through two layers of filter paperDistil the water first, then filter the soil from the distillateLet the soil settle, then evaporate the water to collect the vinegar

19.

A solution contains 90 g of solute K in 100 mL of water at 60 °C. It is cooled to 40 °C and a seed crystal is added so no supersaturation occurs. What mass of crystals forms?

Temperature (°C)	Solubility of K (g/100 mL)
20	32
40	64
60	110

46 g64 g0 g26 g

20.

A 200 g solution is 10% w/w salt. 50 g of water evaporates from it. What is the new concentration?

10%40%13.3%15%

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Year 10 Science – Solutions and Mixtures 1