Y7: Solutions and Solubility

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• Chemistry
• Lower Secondary (Key Stage 3)

Y7: Solutions

Mixtures

Pure substances

A solution is a mixture of one (or more) substances dissolved in a liquid.

Solutions

Solute: the substance(s) that is dissolved in a liquid. 

Solvent: the liquid that dissolves another substance(s).

Miss Buchanan dissolves 3 spoons of coffee powder in some hot water to make her morning cup of coffee.

Solute:

Solvent:

Solution:

Coffee powder

Hot water

Strong coffee

Miss Buchanan use a dishwasher tablet in the dishwasher to clean her plates.

Solute:

Solvent:

Solution:

Dishwasher tablet

Hot water

Soapy water

Miss Buchanan adds 4 spoons of cocoa powder to warm milk to make herself a tasty hot chocolate.

Solute:

Solvent:

Solution:

Cocoa powder

Warm milk

Hot chocolate

The sugar is the...

A

Solute

B

Solvent

C

Solution

D

The liquid is the...

A

Solute

B

Solvent

C

Solution

D

B is the...

A

Solute

B

Solvent

C

Solution

D

C is the...

A

Solute

B

Solvent

C

Solution

D

Milk is the...

A

Solute

B

Solvent

C

Solution

D

Nesquik is the...

A

Solute

B

Solvent

C

Solution

D

A mixture of a substance (solid, liquid or gas) and a liquid.

A substance (solid, liquid or gas) that is dissolved in a liquid.

A liquid in which a substance dissolves.

Match the words to the definitions.

Solvent

Solute

Solution

Is this substance soluble?

A

Yes

B

No

C

D

Is this substance soluble?

A

Yes

B

No

C

D

Some substances dissolve in one solvent, but not another.

If I kept adding sugar, what would happen?

Solubility = the maximum mass of a substance that will dissolve (in 100g of solvent). 

How will increasing the temperature effect a substances solubility?

1

Less of the substance will dissolve.

2

More of the substance will dissolve.

3

The mass of substance dissolving will not change.

Rules:

1. Add one spatula of sugar at a time.

2. All of the sugar must be dissolved before you add the next spatula.

3. Remember to keep count of how many spatulas you have added.

What effect does temperature have on solubility?

Match the words to their definitions.

Solute

Solvent

Solution

Soluble

Insoluble

Solubility

Which substance is insoluble?

A

Baking soda

B

Canola oil

C

Nitrogen

D

Sugar

Which substance is most soluble?

A

Copper sulfate

B

Epsom salts

C

Salt

D

Sugar

Which gas is most soluble?

A

Carbon dioxide

B

Nitrogen

C

Oxygen

D

Alum

What would happen if 20g of baking soda was mixed with 100g of water?

Solubility Curves

Use the graph to find the solubility of the substance at different temperatures.

200

285

325

175

Which is the most soluble substance at 0 C?

$$°$$

A

a

B

b

C

d

D

f

Which is the least soluble substance at 0 C?

$$°$$

A

a

B

b

C

d

D

f

At what temperature do C and E have equal solubility?

A

4

B

23

C

48

D

Never

What is surprising about the solubility of g?

What would happen if 50g of c were added to 100g of water?

Saturated = no more solute will dissolve.