Chemical And Physical Reactions

Question 1

Is there a reaction between lemon juice and bicarbonate of soda?

Answer 1

Yes

Question 2

How do you know there is a reaction between the lemon juice and bicarbonate of soda?

Answer 2

There are bubbles (effervescence)

Question 3

Can the lemon juice and bicarbonate of soda reaction be reversed?

Answer 3

No

Question 4

Is the reaction between the lemon juice and bicarbonate of soda a physical or chemical change?

Answer 4

Chemical

Question 5

Why is the reaction between the lemon juice and bicarbonate of soda a chemical reaction?

Answer 5

Because it has given off a gas

Question 6

Is there a reaction between baking powder and water?

Answer 6

Yes

Question 7

How do you know there is a reaction between baking powder and water?

Answer 7

Effervescence has occurred

Question 8

Can the reaction between baking powder and water be reversed?

Answer 8

No

Question 9

Was the reaction between baking powder and water a chemical or physical change?

Answer 9

It was a chemical change

Question 10

Why was the experiment between baking powder and water a chemical reaction?

Answer 10

A gas was given off

Question 11

Is there a reaction between iron wool and copper sulphate solution?

Answer 11

Yes

Question 12

How do you know there is a reaction between iron wool and copper sulphate solution?

Answer 12

There was a colour change

Question 13

Can the experiment between iron wool and copper sulphate solution be reversed?

Answer 13

No

Question 14

Is the reaction between the iron wool and copper sulphate solution a chemical or physical change

Answer 14

A chemical reaction

Question 15

Why is the reaction between iron wool and copper sulphate solution?

Answer 15

There was a colour change

Question 16

Is there a reaction between starch and iodine?

Answer 16

Yes

Question 17

How do you know there is a reaction between starch and iodine?

Answer 17

There was a colour change

Question 18

Can the reaction between starch and iodine be reversed?

Answer 18

no

Question 19

Is the reaction between starch and iodine a chemical or physical change?

Answer 19

It’s a chemical change

Question 20

How do you know the reaction between starch and iodine is a chemical?

Answer 20

A colour change

Question 21

Is there reaction between salt and water?

Answer 21

No

Question 22

How do you know there isn’t reaction between salt and water?

Answer 22

Dissolving isn’t a reaction

Question 23

Can the ‘reaction’ between salt and water be reversed?

Answer 23

Yes

Question 24

Is the experiment with water and salt a chemical or physical change?

Answer 24

A physical change

Question 25

In the experiment melting ice is there a reaction?

Answer 25

No

Question 26

Could the experiment of ice melting be reversed?

Answer 26

Yes

Question 27

What is a chemical reaction?

Answer 27

A chemical reaction is two substances (reactants) react together to make one or more new substances (products)

Question 28

Is a chemical reaction irreversible?

Answer 28

Usually a chemical reaction is irreversible meaning it is impossible to reverse the reaction and get the original substances back

Question 29

How does the physical reaction occur?

Answer 29

If a change happens to a substance but no new product is made then it is called a physical change

Question 30

Name some chemical reactions:

Answer 30

``` Adding an acid to an alkali Fireworks Driving a car Frying an egg Burning a candle Lighting a match Baking a cake Launching a space rocket ```

Question 31

Name some physical reactions:

Answer 31

``` Ice cream melting Boiling the kettle Melting candle wax Dissolving sugar in tea Making ice cubes Ironing clothes Printing ```