Chemical Reactions

Question 1

Give 6 things that can happen when a chemical reaction occurs:

Answer 1

• Temperature change
• Gas is produced
• Explosion
• Colour change
• Dissolving
• Sound

Question 2

What is the definition of a chemical reaction?

Answer 2

A chemical reaction is a change that results in the formation of one or more new substances

Question 3

How does a chemical reaction work?

Answer 3

The reactants are formed into new products

Question 4

What are the two types of changes?

Answer 4

Physical & chemical

Question 5

What is a physical change?

Answer 5

The change of a substance from one state to another

Question 6

Is a new substance formed during a physical change?

Answer 6

No

Question 7

Give 3 examples of a physical change :

Answer 7

Glass breaking, Ice melting folding paper

Question 8

What physical change is generally considered a chemical change?

Answer 8

Water melting

Question 9

Give an example of a chemical change

Answer 9

Rusting

Question 10

Can chemical changes be reversed? Give an example of why?

Answer 10

No. Baking a cake you cannot take the flour back out

Question 11

What do chemical reactions involve? Give an example

Answer 11

An energy change, eg fireworks give off light, heat & sound

Question 12

Give 3 signs of a chemical reaction

Answer 12

• gas is produced
• a colour change
• heat is produced
• light is produced
• sound is produced
• electricity is produced

Question 13

When was Antoine Lavoisier alive?

Answer 13

1743 - 1749

Question 14

What was Antoine Lavoisier Law?

Answer 14

Law of Conservation of Mass

Question 15

What did Antoine show?

Answer 15

He showed that mass was not created or lost in a chemical reaction

Question 16

What does the Law of Conservation of Mass state?

Answer 16

It states that matter cannot be created or destroyed, but can only be changed from one form to another

Question 17

In any chemical reaction what is always equal?

Answer 17

The total mass of the reactions & the total mass of the products

Question 18

What is a reactant?

Answer 18

Substances that react together

Question 19

What is a product?

Answer 19

They are the substances that are formed by the end of a chemical reaction

Question 20

What is the definition of activation energy?

Answer 20

The minimum energy needed to start a chemical reaction

Question 21

What is an exothermic reaction?

Answer 21

When after the reaction the energy is lower then it was before

Question 22

What is an endothermic reaction?

Answer 22

After the reaction the energy is higher than at the start

Question 23

What is the definition of rate of reaction?

Answer 23

It is the change in concentration per unit of time of any one reactant or product

Question 24

How do we measure the rate of reaction?

Answer 24

We measure it by measuring how the concentration ( how much of something you have) of any one reactant or product changes with time

Question 25

What is the formula for the rate of reaction?

Answer 25

Change in concentration of any reactant/ Time taken

Question 26

What causes chemical reactions?

Answer 26

Collins between particles are what causes chemical reactions

Question 27

What happens when particles collide really fast?

Answer 27

The reaction is more likely to happen

Question 28

Give the 5 factors affecting the rate of reaction:

Answer 28

1. Types of reactants 2. Particle size 3. Concentration 4. Temperature 5. Catalysts

Question 29

What does the rate of reaction depend on, in relation to types of reactants?

Answer 29

It depends on the type of chemicals reacting together

Question 30

What does the rate of reaction do in relation to the concentration?

Answer 30

Increases

Question 31

Is a larger or smaller particle better for faster reactions?

Answer 31

Smaller

Question 32

What happens you increase the particle size ?

Answer 32

It increases the number of particles that are exposed to other reactants

Question 33

Is the rate of reaction greater at higher or lower temperatures ?

Answer 33

Higher

Question 34

Whats the definition of a catalyst?

Answer 34

A substance that alters the rate of a chemical reaction but is not used up in the reaction

Question 35

What are biological catalysts?

Answer 35

Enzymes

Question 36

Give 2 examples of biochemical reactions:

Answer 36

- photosynthesis - digestion

Question 37

What is a biochemical reaction?

Answer 37

A reaction that is occurring inside something that is biological

Question 38

What is the branch of science called that studies chemical reactions in living things?

Answer 38

Biochemistry

Question 39

Are their chemical reactions occurring in your body everyday? If so, how many?

Answer 39

Yes, thousands

Question 40

What is quantitative data? Give an example.

Answer 40

Data consisting of numbers. Shoe size

Question 41

What is qualitative data?

Answer 41

Data consisting of words. Favourite colour