Reactions Y8

Question 1

What is the pH range of an acid?

Answer 1

1-6

Question 2

What is the pH range of an alkali?

Answer 2

8-14

Question 3

What is the pH of a neutral substance?

Answer 3

7

Question 4

What colour will universal indicator go in an acid?

Answer 4

Red/Orange

Question 5

What colour will universal indicator go in an alkali?

Answer 5

Blue/Purple

Question 6

Are physical changes reversible?

Answer 6

Yes

Question 7

Are chemical reactions reversible?

Answer 7

No

Question 8

What is the difference between physical and chemical reactions

Answer 8

In physical bonds are made or broken in chemical atoms are rearranged to create new substances

Question 9

Is oxidation reversible

Answer 9

No

Question 10

What is the law of conservation of mass?

Answer 10

mass of reactants = mass of products

Question 11

Which sides of a chemical reaction is the reactants and which one is the products

Answer 11

Reactants —> products

Question 12

If there is a reaction where the mass increases where did the extra mass come from?

Answer 12

A place that could source the other reactant that was not controlled like the air could add oxygen into a reaction

Question 13

What is an exothermic reaction

Answer 13

A reaction where energy is transferred to the surroundings

Question 14

What is an endothermic reaction

Answer 14

A reaction that takes in energy from its surroundings

Question 15

How are endothermic reactions helpful

Answer 15

Cool packs, melting

Question 16

How are exothermic reactions helpful

Answer 16

Fire, freezing

Question 17

How can we test if a reaction is exothermic or Endothermic

Answer 17

Measure temperature before and after reaction and look for light being given off or not

Question 18

In endothermic reactions and exothermic reactions are bonds broken or formed

Answer 18

Endothermic: bonds made
Exothermic: bonds

Question 19

What is a catalyst

Answer 19

Substance that speeds up the rate of a chemical reaction

Question 20

What is the benefits of using catalysts in industry

Answer 20

To be more efficient, cost effective and eco friendly

Question 21

How do catalysts speed up reactions

Answer 21

By reducing the amount of energy needed

Question 22

Is combustion exothermic or endothermic

Answer 22

Exothermic

Question 23

What is the word equation for combustion of methane

Answer 23

methane + oxygen -> carbon dioxide + water

Question 24

What is the symbol equation for combustion of methane

Answer 24

CH4 + 2O2 -> CO2 + 2H2O

Question 25

Name 3 fuels

Answer 25

Methane, ethanol, wood, coal, oil

Question 26

What is the conclusion of an experiment

Answer 26

What you figure out or prove from the experiment

Question 27

What is it called when oxygen reacts with metal

Answer 27

oxidation

Question 28

What is a word equation for oxidation in iron

Answer 28

Iron + oxygen -> iron oxide (rust)

Question 29

What is thermal decomposition

Answer 29

1 reactant breaking down into 2 or more products

Question 30

What are the word equations for thermal decomposition

Answer 30

Metal carbonate -> metal oxide + carbon dioxide

Question 31

Write the chemical equation for the thermal decomposition of calcium carbonate

Answer 31

CaCO3 -> CaO + CO2

Question 32

What are the different types of fire extinguishers

Answer 32

Water, foam, carbon dioxide, powder, wet chemical

Question 33

What are the three sides of the fire triangle

Answer 33

Heat, Fuel, Oxygen

Question 34

How do fire extinguishers work?

Answer 34

By removing one side of the fire triangle e.g. water removes heat