states of matter & mixtures

Question 1

Describe the structure of solids.

Answer 1

• regular arrangement
• particles packed close together
• vibrate in fixed position
• definite shape & volume

Question 2

Describe the structure of liquids.

Answer 2

• random arrangement
• particles close but can move around
• definite volume, no definite shape

Question 3

Describe the structure of gas.

Answer 3

• random arrangement
• particles far apart
• no definite shape & volume

Question 4

When particles change state by adding or removing energy, the change is… making them… changes.

Answer 4

reversible

physical

Question 5

Name these state changes:
- solid to liquid
- liquid to gas
- gas to liquid
- liquid to solid

Answer 5

• melting
• evaporation
• condensation
• freezing

Question 6

Define:
- solute
- solvent
- solution

Answer 6

• substance can be dissolved in a solute
• substance dissolves a solute
• mixture of solute & solvent

Question 7

Describe distillation:

Answer 7

Liquid heated to boiling point to vaporise it, then condensed back into a liquid so it’s separated from impurities.

Question 8

Describe chromatography:

Answer 8

Separation technique used to separate mixtures of soluble substances.

Question 9

Describe filtration:

Answer 9

Use a filter to separate an insoluble solid from a liquid.

Question 10

Describe crystallisation:

Answer 10

Formation of solid crystals from a solution by allowing solvent to evaporate slowly.

Question 11

What is a pure substance?

Answer 11

A substance made up of only one kind of particle.

Question 12

What is a mixture?

Answer 12

Substance made from combination of different particles.

Question 13

What type of melting points do pure substances have vs mixed substances?

Answer 13

Pure - lower than 5 degrees
Mixed - higher than 5 degrees

Question 14

What is the method for filtration?

Answer 14

1. Place filter funnel in conical flask
2. Fold filter paper & place in funnel
3. Pour mixture through filter paper
4. Remove paper and sand
5. Pour your salt water into evaporation basin
6. Put evaporation basin on tripod
7. Light bunsen burner

Question 15

What’s the method for chromatography?

Answer 15

1. Measure 1cm from bottom of paper & draw a dot of ink
2. Attach top of paper to splint with paper clip
3. Place paper & splint in empty beaker
4. Fill beaker with water, covering bottom of paper but not ink
5. Calculate results

Question 16

What is the formula for Rf in chromatography?

Answer 16

Distance moved from start of pencil line/distance of solvent from start of line

Question 17

What is the method for crystallisation?

Answer 17

1. Place tripod & gauze mat over bunsen burner
2. Pour copper sulfate solution into evaporating dish
3. Place evaporating dish on tripod
4. Turn bunsen burner on & observe