Investigating the effects of electrolysis on aqueous solutions using inert electrodes.
To perform this experiment, we will need the following apparatus:
1. Use a measuring cylinder to add the aqueous solution to the beaker.
2. Place the two graphite rods (the electrodes) into the aqueous solution.
3. Place a test tube over each electrode to collect the gases.
4. Turn on the power supply and allow electrolysis to take place.
It is important to take necessary safety precautions while performing this experiment, such as wearing goggles and gloves. Also, ensure the proper disposal of the electrolyte solutions after the experiment is completed.
Hydrogen – Place a lighted splint in the test tube containing the gas. If it contains hydrogen, then the splint will go out and there will be a squeaky pop.
Oxygen – Place a glowing splint in the test tube. If the splint relights, the gas is oxygen.
Chlorine – Place damp blue litmus paper in the test tube. If the litmus paper turns red and then is bleached white, the gas is chlorine.
Record your results in an appropriate table. For example:
|Electrolyte||Observation at negative electrode, including gas test results||Observation at positive electrode, including gas test results|
|Dilute sodium chloride||Effervescence, no colour, lighted splint goes out with a squeaky pop → Hydrogen gas||Effervescence, pale green gas, blue litmus paper turns red then white → Chlorine gas|
Compare your experimental results with the expected outcomes from your hypothesis. For example, mention if your hypothesis is supported by the observation. If your results do not match the hypothesis, discuss possible sources of error or factors that may have influenced the outcome.