It is the quantitative study of
reactants and products in a chemical
reaction.
It also studies the proportion of the
different elements in a chemical
compound and the composition of
chemical mixtures.
These Calculations can be made with
chemical reactions and are based on
weight laws.
1.Law of conservation of mass
In a chemical reaction, the sum of the mass of
the reactants equals the sum of the mass of the
products.
2. law of constant proportions
A chemical compound is always formed by the
same mass proportion of its constituent elements
regardless of the method of preparation or source
of obtaining.
4. Law of combination volumes
when gases react together they do so in volume which bears
simple whole number ratio provided that the temperature
and pressure of the reacting gases and their products remain
constant.
3. Law of multiple proportions
when two elements combine with each other to
form more than one compound, the weights of
one element that combine with a fixed weight of
the other are in a ratio of small whole numbers
Stoichiometric calculations
to calculate the amount of product formed in an
equation we use moles. This method is called the mole
method.
The basic premise of the mole ratio method of stoichiometric calculations is that the
relative numbers of moles of reactants and products remain the same regardless of the
total quantity of reaction.
You must master the following chemistry concepts to solve
stoichiometry problems: Balancing equations, Converting
between grams and moles, Calculating molar mass
,Calculating mole ratios.
Limit Reactive and Excess Reactive
The limiting reactant would be used up before the other reactant,
while the excess reactant would be the one leftover after the
reaction proceeded.