Chemical Changes

Question 1

Acid definition

Answer 1

Any substance that forms an aqueous solution with ph 7 or less

They ionise in aqueous solutions, releasing H+ ions

Question 2

Bases definition

Answer 2

Any substance that can neutralise an acid

Question 3

Common examples of bases:

Answer 3

• Naked metals
• Metal Oxides
• Metal Hydroxide
• Metal Carbonates

Question 4

Alkalis are an example of __________ bases

Answer 4

soluble

Question 5

How are salts formed?

Answer 5

When the hydrogen ions in an acid are replaced with metal or ammonium ions (in a neutralisation reaction)

Question 6

Alkalis are compounds that release _____ when dissolved in water

Answer 6

OH- ions

Question 7

Sulfuric acid

Answer 7

H2SO4

Question 8

Nitric acid

Answer 8

HNO3

Question 9

Hydrochloric acid

Answer 9

HCl

Question 10

whereas strong acids completely ionise in aqueous solutions, with weak acids…

Answer 10

only a small percentage of their molecules split up into ions

Question 11

Neutralisation

Answer 11

when an acid and base react to give salt + water

Question 12

acid + metal ->

Answer 12

salt + hyrdrogen

Question 13

acid + metal oxide ->

Answer 13

salt + water

Question 14

acid + metal hydroxide ->

Answer 14

salt + water

Question 15

acid + metal carbonate ->

Answer 15

salt + water + carbon dioxide

Question 16

During a neutralisation reaction, the positive hydrogen ions from the acid react with the negative ___________ ions from the ____________

Answer 16

1. hydroxide
2. alkali

Question 17

Strong acids _________ completely, so all of the acid particles will _______ to release ___ ions in aqueous solutions

Answer 17

1. ionise
2. dissociate
3. Hydrogen

Question 18

Examples of strong acids

Answer 18

hydrochloric acid

sulfuric acid

nitric acid

Question 19

symbol: hydrochloric acid

Answer 19

HCl

Question 20

symbol: sulfuric acid

Answer 20

H2SO4

Question 21

symbol: nitric acid

Answer 21

HNO3

Question 22

In aqueous solutions, only a _______ proportion of the acid particles ______.

Answer 22

1. small
2. dissociate

Question 23

Ionisation of a weak acid is….

Answer 23

REVERSIBLE

Question 24

Examples of weak acids

Answer 24

Ethanoic Acid

Citric Acid

Carbonic Acid

Question 25

The higher the concentration of hydrogen ions, the _______ the pH

Answer 25

lower

Question 26

pH scale = the concentration of...

Answer 26

H+ ions

Question 27

REDOX -

Answer 27

oxidation and reduction simultaniously

Question 28

Oxidation

Answer 28

lose electrons gain oxygen

Question 29

Reduction

Answer 29

lose oxygen gain electrons

Question 30

ionic equations will only show the particles that...

Answer 30

take part in the reaction and change in some way from left to right... write them out with their charge specified i.e. make it obvious that they are ions.

Question 31

Half equations are the ionic equation but only showing the change of...

Answer 31

1 element