Stoichiometry

Stoichiometry

It’s about calculating how much of each reactant is needed and how much product will be made in a chemical reaction, based on the balanced chemical equation. There is a proportional relationship between two or more substances during a chemical reaction. These calculations allow for predictions about the amount of product that can be produced from a given amount of reactions.

Why is stoichiometry important?

it allows us to quantify the relationships between reactants and products in chemical reactions.

mole ratios

A conversion factor that relates the amounts in moles of any two substances involved in a chemical reaction a

limiting and excess reactant

LR/ substance that controls quantity of product that can form in a chemical reaction- LR is the one that produces the least amount

ER/ substance that’s not completely used up in a chemical reaction- ER is the one that produces the most

Theoretical Yield

The maximum quantity of product that a reaction could make if everything about the reaction works perfectly

The TY is always the smaller number between the ER and LR. (THE LR)

Actual yield

The mass of the product actually formed. Always less that TY and it’s given to you in the problem, although it can be tricky to identify.

Equation/ (actual yield/ theoretical yield x 100)

Calculating excess

Subtract the 2 theoretical yields, do a g to g using that. Make sure the answer of that is not higher than the stating amount, then subtract the answer you got from the g to g from the starting amount

Yields over 100

Yields over 100% aren’t valid as they are a violation of the law of conservation of mass