Topic 2 - (reactions) Flashcards Preview

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Flashcards in Topic 2 - (reactions) Deck (28)
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1

What does the law of conservation of mass mean?

That mass is never lost or gained in chemical reactions

2

If the .......... is a gas, you will observe a mass increase

reactant

3

If the .......... is a gas, you will observe a mass decrease

Product

4

What is combustion?

When a fuel reacts with oxygen to release energy

5

What are 3 things needed to make a combustion?

- fuel
- heat
- oxygen

6

What is oxidation?

When a substance reacts and combines with oxygen

7

Combustion is a type of ............ reaction

Oxidation

8

What is the equation of rusting?

Iron + oxygen - iron oxide (rust)

9

What is iron oxide?

Rust

10

Exothermic reactions....

Release heat

11

Endothermic reactions....

Take in heat

12

Which reactions are exothermic?

Neutralisation and oxidation

13

Which reactions are more common? Exothermic or endothermic?

Exothermic

14

Which reactions are also endothermic reactions?

Thermal decomposition reactions

15

What is a thermal decomposition reaction?

A reaction that uses heat to break down a substance into smaller molecules

16

What is an example of a thermal decomposition reaction?

CaCO3 - CaO + CO2
(Making lime from lime water!)

17

What do carbonates produce when they decompose?

Carbon dioxide

18

Name 3 uses of thermal decomposition reactions

- Making lime from lime water
- Extracting Mercury
- Thermal cracking

19

What is a precipitation reaction?

A reaction in which a solid is made

20

What is the precipitate in a reaction?

The solid

21

What does the state symbol (aq) mean?

Dissolved into solution

22

What do reactions involve?

A transfer in energy

23

What is an example of a precipitation reaction? And what is the precipitate

Potassium iodide (aq) + lead nitrate (aq) - potassium nitrate (aq) + lead iodide (s)

Precipitate: LEAD IODIDE (s)

24

What is CaCO3?

Limestone

25

What is iron oxide? ( FeO)

Rust

26

In a chemical reaction, WHY is there no change in mass?

Because you can’t create or destroy atoms

27

What can oxidation reactions be used to make?

Acids and bases

28

What is an example of an endothermic reaction?

- Sodium hydrogen carbonate + hydrochloric acid
- photosynthesis