How to know the product has formed during refluxing?

Question

how to determine the Stoichiometry a reaction in order to synthesis a compound?

Answer 1

It depends on the reaction, sometimes you can tell by a colour change or by a precipitate. Usually the reaction you will do will have been done before so you should be able to find out how long and at what temperature is needed for good results. The only real way to find out is to look at your product afterwards, identify using spectroscopy and assess purity using chromatography and melting point. But before doing this take the mass and use this alongside its purity and mass of the reactants to work out stoichiometry