Question

While electrolysing water before passing the current some drops of an acid are added. Why? Name the gases liberated at cathode and anode. Write the relationship between the volume of gas collected at anode and the volume of gas collected at cathode.

Answer 1

Acid is used to increase the conductivity of water. The gas released at the cathode is hydrogen H₂, and the gas released at the anode is oxygen O₂. The volume of hydrogen and oxygen gases collected at respective electrodes is always in the ratio of 2: 1, where hydrogen being twice as large as oxygen.