Practicals Flashcards
How do you prepare a pure dry salt
Measure 20 cm° sulfuric acid into a measuring cylinder and pour it into beaker.
2. Heat the acid gently using a Bunsen burner.
3. Add small amounts of insoluble base in this case copper oxide in excess (until no more reacts thus no more effervescence is produced).
4. Filter using filter paper and funnel the solution to remove the excess copper oxic
5. Pour the solution into the evaporating basin.
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6. Evaporate the solution using a water bath until crystals start to form.
7. Leave the evaporating basin in a cool place for at least 24 hours.
8. Gently pat the crystals dry between two pieces of filter paper.
Temp changes practical
Measure 25cm° of hydrochloric acid into a polystyrene cup.
2. Place the cup inside the beaker to make it more stable.
3. Measure and record the temperature of the hydrochloric acid.
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4. Measure 5cm° of sodium hydroxide and add it to the polystyrene cup.
5. Quickly put a lid on the cup and gently stir the solution with the thermometer through the hole of lid.
6. When the reading on the thermometer stops changing and becomes fairly constant, record the temperature.
7. Repeat steps 4 and 5 to add further 5 cm° amounts of sodium hydroxide to the cup. A 51 minimum total of 40 cm° needs to be added.
8. Repeat steps 1-7 to ensure reliability of results.
9. Calculate the mean maximum temperature reached for each of the sodium hydroxid volumes
Electroylsjs practical
- Add about 50cm” of copper chloride solution to a beaker.
- Add the lid and insert electrodes through the holes making sure the electrodes don’t
touch - Attach crocodile leads to the electrode and connect the rods to the DC terminals of a voltage power supply.
- Set the power supply to 4V and switch the power supply on.
b. Using the forceps hold the litmus paper near the positive electrode - After a few minutes turn the power supply oft and observe the negative electrode.
- Record observations at the electrodes.
