Question 7.
Water decomposes into hydrogen and oxvgen during electrolysis. A sample of water is electrolysed.
The hydrogen and oxygen are collected separately. After ten minutes, the volumes of hydrogen and
oxygen are measured. Two further experiments are carried out, changing only one factor in each
experiment. All other factors are kept the same. The table shows the conditions and results for all
three experiments.

Analyse this data to explain the effect of changing the time and the current on the volumes of
hydrogen and oxygen produced.
(6marks)