Required Practicals 1-8

Question 1

How can you separate insoluble solids form a liquid?

Answer 1

Filtration

Question 2

What is titration?

Answer 2

It allows you to find the exact volume of acid needed to neutralise a quantity of alkali or vice versa. This can then be used to find the necessary concentrations

Question 3

What chemicals are used in titration?

Answer 3

0.1mol/dm3 sodium hydroxide
Dilute sulphuric acid of unknown concentration

Question 4

What indicator is used in titration and what colour is it turn from and to?

Answer 4

Phenolphthalein - from pink (alkali) to clear (acid)

Question 5

How do you do required practical 1 preparing a soluble salt?

Answer 5

1. Mix copper 2 oxide with sulfuric acid in a beaker
2. When copper is in excess filter it out into a conical flask
3. Pour filtrate into evaporating basin
4. Place evaporation basin over water beaker - (water bath)
5. Pour into crystallising dish and leave for 24 hours

Question 6

How do you do practical 3 - electrolysis?

Answer 6

1. Pour copper 2 chloride into the beaker
2. Insert carbon rods without them touching
3. Connect up the circuit with a 4V dc power supply
4. Repeat experiment with sodium chloride
5. Wrote down the results

Question 7

How do you do practical 4 - temp change?

Answer 7

1. Put dilute hydrochloric acid into a polystyrene cup
2. Stand cup in beaker with a thermometer
3. Measure 5cm3 of sodium hydroxide and add
4. Gently stir through lid with thermometer
5. Measure the maximum temperature after it stops changing
6. Repeat untill the solution has 40cm3 sodium hydroxide