In a titration you put a limited amount (the aliquot) in the flask and have an excess amount in you burette. You then run the titrant into the flask, making a reaction until there is a color change, which means that the aliquot has all been used up. Therefore the substance in the flask is the limiting reagent. read more
The limiting reagent is the one with the lower millimoles. To get the ml of excess reagent, find the difference between the non-limiting reagent and the limiting reagent, and divide by the molarity of the non-limiting reagent. read more