Question

Acidulated water is electrolysed using platinum electrodes.

Answer the following questions:

1. Why is dilute sulphuric acid added to water?
2. Write the reaction taking place at the cathode.
3. What is the observation at the anode?

Answer 1

1. Dilute sulphuric acid is introduced to water during electrolysis with platinum electrodes to increase the water’s conductivity, as pure water is a poor conductor of electricity due to its low ion concentration.
2. At the cathode, H⁺ ions from the acid gain electrons and form hydrogen gas.
   \[\ce{2H+ + 2e- -> H2\uparrow}\]
3. A bubble of colourless gas oxygen evolves at the anode.