EL9 How Salty?

Question 1

What is an acid?

Answer 1

A compound that DONATES hydrogen ions (protons) in a solution
- proton donor

Question 2

What is a base?

Answer 2

• chemical that ACCEPTS protons

- proton acceptor

Question 3

Acid + alkali =

Answer 3

Salt + water

Question 4

Acid + base =

Answer 4

Salt + water

Question 5

Acid + carbonate =

Answer 5

Salt + water + carbon dioxide

Question 6

Acid + metal =

Answer 6

Salt + hydrogen

Question 7

Acid + metal oxide =

Answer 7

Salt + water

Question 8

What is the name of this acid H2SO4(aq)?

Answer 8

Sulphuric acid

Question 9

Name and write formula of common alkali

Answer 9

Sodium hydroxide, NaOH
Potassium hydroxide, KOH
Ammonia, NH3

Question 10

Define alkali

Answer 10

A base that dissolves in water

- forms hydroxide (OH-) ions

Question 11

What is a salt?

Answer 11

Compound formed when hydrogen ion in an acid is replaced with a metal ion or ammonium ion

Question 12

Give some properties of acids

Answer 12

• turns litmus paper red

- neutralised by bases

Question 13

What do organic acids contain?

Answer 13

Carboxyl group (COOH)

Question 14

Give equation for sulphuric acid and water

Answer 14

H2SO4(l) + H2O = H3O+(aq) + HSO4-(aq)

Question 15

What occurs when an acid and a base react?

Answer 15

They neutralise each other

Question 16

Define concentration

Answer 16

A measure of how much solute is dissolved in a certain volume of solvent

Question 17

How do you work out concentration? (From moles and volume)

Answer 17

Number of moles/volume

Question 18

What is titration used for?

Answer 18

To determine concentration of a solvent

Question 19

Give method of volumetric analysis (titration)

Answer 19

1. Standard solution is measured with volumetric pipette, put in conical flask with indicator
2. Calculate number of moles in solution
3. Using burette, add unknown solution until colour changes
4. Calculate number of moles that reacted (using volume used) and calculate concentration