In this explore lab we experimented with the reactions of white powders and vinegar. We had set amounts of one variably and the other variable amount varied. We found the class data to be unpredictable because some people had errors throughout the lab, but what we could decipher from the data was that the graph of the data was linear at first and then eventually plateaued. The reason for this was, for example, if you add baking soda you add to a constant amount of vinegar it will keep increasing but eventually there will be too much baking soda to to little vinegar. This is where the limiting reactant comes into play. In this example the vinegar is the limiting reactant. This can be predictable for set elements and solutions because you have data that you can infer the future possibilities with. The limiting reactant is how much of a substance you need to make an experiment possible. The excess reactant is how much you have left over from the other compound or solution. These reactants can always be determined by the balanced equation. You can calculate how much of the excess reactant is left over by using the molar ratio in the balanced equation.
For more information on Stoichiometry Check out this video!