4.1-4.4 Balanced Chemical Equations, Stoichiometry

4.1 Climate Change and the Combustion of Fossil Fuels, 4.2 Writing and Balancing Chemical Equations, 4.3 Reaction Stoichiometry, 4.4 Stoichiometric Relationships

chemical reaction

a process by which one or more substances convert to one or more different substances

chemical equation

a symbolic representation of a chemical reaction, a balanced equation contains equal numbers of the atoms of each element on both sides of the equation

reactants

the starting substances of a chemical reaction; they appear on the left-hand side of a chemical equation

products

the substances produced in a chemical reaction; they appear on the right-hand side of the chemical equation

(g), (l), (s), (aq)

states of reactants and products in chemical equations are represented using parentheses:

• ___ - gas

• ___ - liquid

• ___ - solid

• ___ - aqueous (water solution)

coefficients

numbers in front of the chemical formulas, specify the relative amounts in molese of each of the substances involved in the reaction

subscripts

numbers within the chemical formulas

balanced chemical equation

a symbolic representation of a chemical reaction; a balanced equation contains equal numbers of the atoms of each element on both sides of the equation

stoichiometry

the numerical relationships between amounts of reactants and products in a balanced chemical equation

limiting reactant

aka limiting reagent, the reactant that has thee smallest stoichiometric amount in a reactant mixture and consequently limits the amount of product in a chemical reaction

excess reactants

the reactants that do not limit the amount of product

theoretical yield

the greatest possible amount of product that can be made in a chemical reaction based on the amount of limiting reaactant

actual yield

the amount of product actually produced by a chemical reaction, always equal to or less than the theoretical yield

percent yield

the percentage of the theoretical yield of a chemical reaction that is actually produced; the ratio of actual yield to the theoretical yield multiplied by 100%

• %yield = (actual yield)/(theoretical yield) * 100%