Chemical Changes

Question 1

What happens with oxidation and reduction?

Answer 1

They happen at the same time.

Question 2

Create a pneumonic for the reactivity series.

Answer 2

Potatoes
Scare
Little
Cat
Magazines
And
Catastrphic
Zebras
Into
Taking
Lethal
Hydrogen
Cups of
Sodium
Goldidium
Plants

Question 3

What is the reactivity series?

Answer 3

Potassium
Sodium
Lithium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Iron
Tin
Lead
Hydrogen
Copper
Silver
Gold
Platinum

Question 4

What happens in displacement reactions?

Answer 4

A more reactive metal will displace a less reactive metal from a solution of its salt.

Question 5

How can metals less reactive that carbon be extracted from their oxides and how does this happen?

Answer 5

Heating with carbon. As carbon is more reactive than the metal, it will displace it and replace it as the more reactive one.

Question 6

What does OILRIG stand for?

Answer 6

Oxidation Is Loss of electrons Reduction Is Gain of electrons

Question 7

What is extraction?

Answer 7

Extracting an element from a compound.

Question 8

What are examples of extraction techniques?

Answer 8

Displacement reactions, electrolysis.

Question 9

What happens when a substance dissolves in water?

Answer 9

They dissociate into their individual ions.

Question 10

What ions make solutions alkaline?

Answer 10

hydroxide ions, OH^-(aq)

Question 11

What ions make solutions acidic?

Answer 11

hydrogen ions, H^+(aq)

Question 12

How can the pH of a solution be measured?

Answer 12

pH probe, universal indicator

Question 13

What is the name for soluble bases?

Answer 13

alkalis

Question 14

How are acids neutralised?

Answer 14

by bases

Question 15

What is the product of: acid + metal hydroxide ?

Answer 15

salt + water

Question 16

How does the reaction of an acid and a base product e water?

Answer 16

The H^+ ions in the acid reaction with the OH^- in the alkali (base) to produce H(2)O (water).

Question 17

What can acids be neutralised by?

Answer 17

metal hydroxide
metal oxide
metal carbonate

Question 18

List neutralisation reaction.

Answer 18

acid + metal hydroxide -> salt + water
acid + metal oxide -> salt + water
acid + metal carbonate -> salt + water + carbon dioxide

Question 19

How is a salt produced?

Answer 19

When the hydrogen in the acid is replaced by a metal ion.

Question 20

How can soluble salts be made?

Answer 20

Through reacting acids with insoluble bases.

Question 21

Describe a practical about preparing a pure, dry sample of a soluble salt from an insoluble oxide/carbonate.

Answer 21

Add metal oxide/carbonate to a warm solution of acid until it reacts no further.
Filter excess metal oxide/carbonate so only the salt remains.
Warm the salt solution until liquid evaporates and forms salt crystals.

Question 22

What’s the difference between weak acids and strong acids upon entering water?

Answer 22

Strong acids are fully ionised; weak acids are only partially.

Question 23

What is an example of a weak acid?

Answer 23

ethnic

Question 24

What is a pH solution the measure of?

Answer 24

H^+ ions

Question 25

What is electrolysis?

Answer 25

The use of an electrical current to break down compounds containing ions into their respective elements.

Question 26

What is the substance being broken down in electrolysis called?

Answer 26

electrolyte

Question 27

Which is the positively charged electrode?

Answer 27

anode

Question 28

Which is the negatively charged electrode?

Answer 28

cathode

Question 29

What is a redox reaction?

Answer 29

When both reduction and oxidation occur.

Question 30

What does a half equation represent?

Answer 30

The ions lost or gained in a redox reaction.

Question 31

How is aluminium extracted using electrolysis?

Answer 31

The aluminium oxide has been mixed with cryolite, which lowers the melting point of the substance requiring less energy and therefore less money.

Question 32

What is an aqueous solution?

Answer 32

When ionic compounds are dissolved in water.