2H+ + 2e H2
At the negative electrode: Cl- and OH- will be attracted. In this case, Cl2 will be given off because it is a halide i.e. a group 7 element.
2Cl- - 2e Cl2
I predict that the higher the voltage, the greater the current will be. So when the voltage is increased at the cathode – the current will be higher, this will mean there are more electrons so more gas will be given off. This is because the flow of electrons and the gas given off are proportional.
PRELIMINARY WORK
We conducted preliminary work, to establish a number of things regarding our experiment.
From the preliminary work we had ascertain a suitable range of voltages to take readings at and a suitable length of time to collect gas for.
We conducted the experiment, as it can be seen in the method, and we trialled at a number of different voltages. When we found a suitable range of voltages we decided to use for the experiment.
The Preliminary work simply involved conducting practise experiments using different voltages for different lengths of time. The results we collected led us to decide that – We should use voltages ranging consistently from 0.2V to 1.2V and collect gas for one minute. The reason for these choices was that they resulted in readings filling little of a measuring cylinder, to filling nearly a whole cylinder respectively. These decisions would hopefully allow us to collect a an accurate set of results
