Question

In the electrolysis of water
(A) name the gas collected at anode and cathode.
(B) why is dilute H2SO4 isadded to water
(C) why is the volume of gas collected at one electrode double than the other

Answer 1

A) Hydrogen will be collected in cathode and oxygen will be collected in anode. Reaction in cathode - H2O(l)+e→1/2H2(g)+OH−(aq) Reactin in Anode - H2O(l)→1/2O2(g)+2H+(aq)+2e B) Electrolysis of pure water is very slow. Water is essentially a covalent compound. Its conductivity can be increased by adding electrolytes like acids. Acids dissociate to produce ions which in turn increase conductivity.So, dilute H2SO4 is added to water. C) Electrolysis is done to split constituents of water . Water composition is 2 atoms of H and 1 atom of O . Therefore H is double than O . The two electrodes collect H and O separately. So we find volume of gas collected in one electrode is double than volume of gas collected in another electrade .