Test

Question 1

What is the chemical reaction?

Answer 1

A chemical reaction takes place when two or more substances combine to make one or more new substances

Question 2

What is a physical change?

Answer 2

A physical change is where are known as substances are made, but there is a change an appearance of a chemical physical changes are not chemical reactions. Examples of physical changes include state changes like changing from a solid to liquid and dissolving physical changes are usually reversible.

Question 3

What are everyday chemical reactions?

Answer 3

Some Aphrodite chemical reactions are cooking rock fuel, burning and digestion, but some not so useful. Chemical reactions is mould growing explosions if not planned and rusting.

Question 4

What is a reactant?

Answer 4

And a chemical reaction the starting substances are called reactants

Question 5

What are products?

Answer 5

Products are new substances formed from reactants

Question 6

What is the chemical change word problem?

Answer 6

Reactants➡️ products

Question 7

How can you identify if a chemical reaction has taken place?

Answer 7

There is a change of colour
Change of temperature
Bubbles of a gas are produced
A perseverate forms (a solid produced when two liquids react)
Light or sound is given out(other forms of energy)

Question 8

What is an example of a chemical reaction?

Answer 8

One example is an iron nail and copper sulphate solution. The iron nail goes slightly red.
Another example is magnesium ribbon and hydrochloric acid the solution fizzled

Question 9

What is a reaction rate?

Answer 9

A reaction rate is how quickly a reaction happens

Question 10

What is a collision?

Answer 10

Chemical reactions only happen when reactants are in contact with each other the reactant particles need to bump into each other for a reaction to a car when the reactant particles do this we call it a collision

Question 11

The more collisions there are between reactants the what happens to the reaction rate

Answer 11

Faster

Question 12

What are some examples of a reaction which scientist tried to

Answer 12

Cooking and manufacturing fertiliser

Question 13

Give an example of reaction rate which scientist try to slow down

Answer 13

Spoiling and rusting

Question 14

How does a higher temperature affect the reaction rate?

Answer 14

A higher temperature equals fast moving particles and more collections

Question 15

How does a lower temperature affect a reaction rate?

Answer 15

A lower temperature equals slow moving particles in less collisions

Question 16

How does particle size affect the speed of a chemical reaction?

Answer 16

By reducing up the particle size we can increase the surface area of the reactant and this increased the reaction rate this is because the larger the surface area the more collisions that can happen between the reactions to which means the reaction will go faster

Question 17

What will the reaction do if it has a high surface area?

Answer 17

It will have more collisions, which means I’ll go faster

Question 18

What will the reaction do if it has a low surface area?

Answer 18

If the reaction has a low surface area that means less collisions in slow reaction rate

Question 19

What is concentration?

Answer 19

Concentration as a measure of how many particles are in certain volume/space. More concentrated solutions have more particles press in the same volume of less concentrated solutions.

Question 20

How many particles do high concentrations in low concentration

Answer 20

High concentrations have many particles will low concentrations have little particles

Question 21

What does increasing the concentration due to an experiment

Answer 21

Increasing a concentration increases the rate of reaction. The higher concentration the faster the reaction rate.

Question 22

What is a catalyst?

Answer 22

A task is a substance which increases the reaction rate of a chemical reaction that is not used up in the reaction

Question 23

What is an example of a catalyst?

Answer 23

Maganese dioxide powder

Question 24

What are the four ways which we can change the reaction rate of a chemical reaction?

Answer 24

Change temperature
Change in concentration
Change a particle size
Add a catalyst

Question 25

What is an enzyme?

Answer 25

An enzyme is a biological catalysts

Question 26

What is a catalase

Answer 26

A catalase as an M which is found in almost all living organisms

Question 27

What is the job of a catalase

Answer 27

It’s job is to speed up the breakdown of hydrogen peroxide into oxygen and water

Question 28

What is the breakdown of hydrogen peroxide into oxygen and water as a word equation?

Answer 28

Hydrogen peroxide➡️ oxygen+ water

Question 29

What is combustion?

Answer 29

Combustion as a chemical reaction which a fuel reacts with oxygen to give out heat energy

Question 30

Can you place the metals in order of reactivity, calcium magnesium zinc in copper?

Answer 30

Most reactive. Calcium.
Magnesium
Zinc
Least reactive Copper

Question 31

What is the name given to metals that react very quickly?

Answer 31

Reactive metals

Question 32

What is the name given to metals that hardly react at all?

Answer 32

Unreactive metals

Question 33

What is needed for iron to rust?

Answer 33

Water and option both need to be present for rust to form

Question 34

What can speed up rusting?

Answer 34

Salt

Question 35

What is the only metal that can rust?

Answer 35

Iron