This kit enables to verify the conditions stated by the law of conservation of mass: the sum of the masses of reactants is equal to the sum of the masses of products. Students can observe that the masses of reactants coincide with those of products and consequently the law of conservation of mass has been complied with. Moreover it is possible to verify that the presence of gaseous substances could alter the results considered by the law of conservation of mass. This is the reason why measurements must be carried out in a closed environment where there is no exchange with the outdoors. In fact, if the system is open, one of the products could suffer some loss.
THEORETICAL – EXPERIMENTAL HANDBOOK