Topic 2 Chemical Changes

Question 1

4 steps when lighting a Bunsen Burner

Answer 1

1. Attach rubber tubing to the gas tap
2. Move the collar until the air hole is 1/3 open
3. Light a wooden splint and hold it above the chimney
4. Turn on gas by moving the gas tap to open

Question 2

Name and spell the 5 parts of the Bunsen Burner shown in the diagram.

Answer 2

A = Barrel/Chimney

B = Regulating collar

C = Air hole with jet inside

D = Gas tubing

E = Base

Question 3

Colour of flame when air hole fully open and 2 other observations

Answer 3

Two toned blue,

Roaring

Hard to see

Question 4

Colour and 2 other observations when the air hole is fully closed

Answer 4

Yellow-Orange flame

Quiet

Easy to see

Question 5

Colour of flame when the air hole is 1/3 open

Answer 5

Yellow flame tinged with blue

Question 6

Colour of flame with sodium

Answer 6

Yellow

Question 7

Colour of flame with potassium

Answer 7

Lilac

Question 8

Colour of flame with strontium

Answer 8

Crimson red

Question 9

Colour of flame with calcium

Answer 9

Brick red

Question 10

Colour of flame with copper

Answer 10

Blue/green

Question 11

Flame colour with barium

Answer 11

Apple green

Question 12

Name the 3 states of matter

Answer 12

solid

liquid

gas

Question 13

What are the missing labels in the the changes of state diagram?

Answer 13

Question 14

A reversible change is…

Answer 14

A change when something is heated that can be changed back on cooling.

Question 15

An irreversible change is

Answer 15

A change on heating that cannot be changed back on cooling

Question 16

Give 3 irreversible changes

Answer 16

magnesium burning or other chemical reaction

wooden splint burning

bread burning or other food cooking

Question 17

Give 3 reversible changes

Answer 17

Changes of state e.g. Ice melting or water boiling/freezing or steaming condensing

Candle wax melting

Sugar/salt dissolving

Question 18

Definition of Soluble

Answer 18

When a substance disolves

Question 19

Defintion of Insoluble

Answer 19

When a substance does not dissolve

Question 20

Definition of Solute

Answer 20

A solid that dissolves in a liquid

Question 21

Definition of Solvent

Answer 21

A liquid that dissolves a solid

Question 22

Definition of Solution

Answer 22

A liquid formed when a solute dissolves in a solvent

Question 23

Draw and label a diagram showing filtration apparatus

Answer 23

Question 24

Draw and label a diagram showing evaporation apparatus

Answer 24

Question 25

When drawing a graph of solubility at different temperatures, what should the label read along the (i) x-axis and (ii) y-axis

Answer 25

x-axis = temperature / ^oC

y-axis = solubility / g/100g water

Question 26

What should you remember when drawing a graph?

Answer 26

Use a pencil and a ruler

Label axis and include units

Use dots with circles for the data points

Smooth single curve/line

Question 27

Draw and label a fire triangle

Answer 27

Question 28

What is the appearance of paper (i) before and (ii) after burning?

Answer 28

Before - white paper

After - dark grey ash

Question 29

Describe what happens when magnesium burns

Answer 29

Bright white flame

Silver metal turns into a white ash