Little litmus is placed in the cathode and the anode compartments of Hoffmann's voltameter containing acidulated water and then electrolysis is carried out. What do you observe and why ?

Little litmus is placed in the cathode and the anode compartments of H

1.	Little litmus is placed in the cathode and the anode compartments of Hoffmann's voltameter containing acidulated water and then electrolysis is carried out. What do you observe and why ?
Answer» Solution :If blue litmus is added to the EATER in Hoffmann's voltameter, the colour of limtus is not changed in cathode compartment since the solution remains alkaline due to increase in `OH^(-)` IONS in the solution due to the discharge of `H^(+)` ions in the solution due to the discharge of `H^(+)` ions at the cathode to GIVE `H_(2)` gas. But blue litmus changes to red in the anode compartment since the `OH^(-)` ions get discharged at anode and the solution becomes rich in `H^(+)` ions. THUS, after ELECTROLYSIS, in cathode compartment, the solution is blue and in anode compartment it is red.