Required Practicals

Question 1

Titration

Answer 1

1. Rinse equipment with distilled water and acid/alkali
2. Measure a known volume of an alkali into a conical flask using a volumetric pipette
3. Add a few drops of indicator
4. Fill the burette with excess acid
5. Release a small amount of acid at a time and swirl the flask to mix the solutions
6. Repeat until the solution turns green
7. Repeat the experiment at least three times. Discard anomalous results and calculate a mean

Question 2

Making a copper salt

Answer 2

1. Add insoluble copper oxide to sulfuric acid in a beaker
2. Heat gently on a tripod & gauze
3. When the solution turns blue and crystals start to form, remove the beaker
4. Filter the solution to remove excess copper oxide
5. Evaporate the water from the solution slowly to give large crystals by a window

Question 3

Electrolysis

Answer 3

1. Dip two electrodes into a melted/dissolved electrolyte solution
2. Connect the anode to the positive terminal and the cathode to the negative terminal of a power supply
3. Positive ions move to the cathode while negative ions move to the anode
4. Ions lose charge and become elements at the electrodes, gases & metals are deposited there

Question 4

Investigating temp. change

Answer 4

1. Measure 30 cm* of hydrochloric acid and pour into a polystyrene cup
2. Record the initial temp. of the solution
3. Measure 5 cm* of sodium hydroxide solution
4. Pour the contents into the cup
5. Place the lid on and stir the contents with the thermometer poked through the lid
6. Record the temperature every minute, stop recording once the temp. stops changing
7. Repeat these steps at least 3 times with the same volume of sodium hydroxide solution, discard anomalies and calculate a mean
8. Repeat this experiment, adding 5cm* more sodium hydroxide solution each time up to 30cm*