Microscale Chemistry Experimentation for Teachers
11.
Syringes for chlor alkali electrolysis
Two 1-ml syringes are used for this experiment
and the electrolysis time is only a few minutes.
* One anode syringe is filled with brine
coloured green with a food dye.
* The anode will be a carbon electrode.
* The second syringe will be filled with
brine
to which a drop of phenolphthalein
was added.
* The cathode electrode to be inserted
into it will be copper.
* A 6-Volt current is applied.
Hydrogen will collect
in the cathode syringe and simultaneously the syringe will be coloured
deep red due to accumulation of hydroxide ions resulting from the reduction
of the water molecule.
Chlorine
will collect in the anode syringe simultaneously decolorizing the food
dye.
The characteristic identification tests
for chlorine and hydrogen can be be applied to the samples generated after
electrolysis................................................Electric
conductivity of solutions