How do I find out which of the two molecules are the limiting reagent for synthesising azo dye? (Dimethylaninline or diazonium salt)

Answer 1

You need to know the balanced equation for the reaction of the two reactants, dimethylaninline and diazonium salt. Once you know that, you also then need to know the amounts of each. You then divide the mols of each by their corresponding coefficient in the balanced equation. Whichever value comes out the least represents the limiting reactant.