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Introduction to Stoichiometry and its Calculations
Stoichiometry is the study of the relative quantities of reactants and products in chemical reactions. It can be used to calculate the amount of a product that will be produced from a given reaction, or the amount of reactants that are necessary to produce a given product.
Stoichiometric calculations are based on the balanced chemical equation for a reaction. This equation states the relative quantities of each reactant and product in the reaction. To perform a stoichiometric calculation, you need to know the molecular weight of each molecule in the equation.
The most basic type of stoichiometric calculation is the calculation of moles. To calculate the number of moles of a substance, you need to know the molecular weight of the substance and the quantity of the substance. Moles can be used to calculate the mass of a substance, the volume of a gas, or the number of particles in a substance.
Another common type of stoichiometric calculation is the calculation of percentages. To calculate the percentage of a substance in a mixture, you need to know the molecular weight of the substance and the quantity of the substance.
Stoichiometry
is the calculation of the amounts of reactants and products in a chemical reaction. In stoichiometry, the coefficients in the chemical equation are used to calculate the relative amounts of each compound that are involved in the reaction.
The stoichiometry of a reaction can be used to determine the amount of a product that is produced, the amount of a reactant that is consumed, or the amount of a product that is needed to produce a desired amount of a reactant.
Chemical Equations
A chemical equation is a symbolic representation of a chemical reaction in which the reactants are on the left and the products are on the right. The equation is balanced when the number of atoms of each element on the left is the same as the number of atoms of the element on the right.
For example, the reaction between magnesium and oxygen can be represented by the following equation:
2Mg(s) + O2(g) -> 2MgO(s)
In this equation, magnesium and oxygen react to form magnesium oxide. The equation is balanced because there are the same number of atoms of each element on both the left and right sides.
Stoichiometric Formulas based on Chemical Reaction
A stoichiometric equation is a mathematical representation of a chemical reaction in which the reactants and products are in their simplest or lowest whole number ratios. In other words, a stoichiometric equation shows the relationship between the amounts of reactants and products in a chemical reaction.
The simplest type of stoichiometric equation is a one-to-one equation in which one molecule of a reactant reacts with one molecule of a product. For example, the equation for the reaction of sodium with chlorine gas to form sodium chloride can be written as:
2Na (g) + Cl 2 (g) → 2NaCl (g)
In this equation, the reactants (sodium and chlorine gas) are on the left-hand side and the products (sodium chloride) are on the right-hand side. The numbers in parentheses indicate the number of molecules of each reactant and product.
Stoichiometric equations can also be written for reactions in which more than one molecule of a reactant reacts with one molecule of a product. For example, the equation for the reaction of hydrogen gas with oxygen gas to form water can be written as:
2H 2 (g) + O 2 (g) → 2H 2 O (g)
In this equation, the reactants (hydrogen and oxygen gas) and products (water) are in their simplest ratios. The numbers in parentheses indicate the number of molecules of
