Acids

Question 1

What’s an alkali

Answer 1

Base that’s soluble in water

Question 2

What’s a base

Answer 2

Chemicals which can neutralise acids and produce a salt and water

Question 3

What happens when acid reactions with a base

Answer 3

Makes salt and water

Question 4

Describe a salt

Answer 4

Contains a positive ion which comes from the base or alkali
Contain a negative ion which comes from the acid

Question 5

Three reactions of acids

Answer 5

Hydrochloric makes chlorides
Sulphuric makes sulphates
Nitric makes nitrates

Question 6

What do acids reduce in aqueous solutions

Answer 6

Hydrogen ions

Question 7

What happens to strong acids in aqueous solutions

Answer 7

Fully ionise as arrow only goes in one direction

Question 8

Examples of strong acids

Answer 8

Hydrochloric acid
Sulphuric acid
Nitric acid

Question 9

What happens to weak acids in aqueous solutions

Answer 9

Partially ionise
= reversible arrow
= some molecules ionised but not all of them

Question 10

Examples of weak acids

Answer 10

Carbonic
Ethanoic
Citric

Question 11

Purpose of pH scale

Answer 11

Gives idea of concentration of hydrogen ions
As scale decreases by one unit, concentration of hydrogen ions increases by 10 times

Question 12

What does concentration of an acid tell us

Answer 12

• Tells us amount of acid molecules in a given volume of solution
• Dilute acid has fewer molecules than concentrated even if strength is the same