A compound is broken down by chemical means during

(1) chromatography

(2) distillation

(3) electrolysis

(4) filtration

Answer : Option 3) Electrolysis.

Explanation : In the process of electrolysis, decomposition of the chemical is done by passing the electric current from the liquid or the solution containing ions in it. This is the process where compound is broken into ions namely, cations and anions.

Rest all options does not involves chemical decomposition of the compound.

Chromatography is a technique where rates of solute and solvent are compared in a medium where the solute components move at different rates and the separation is obtained.

Distillation simply purifies the liquid or solution by heating or cooling process.

Filtration just involves removal of impurities by using a more porous material device to get purified compound.