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12.1 The Arithmetic of Equations • More than 3000 cocoons are needed to produce enough silk to make just one elegant Japanese kimono. Like silk manufacturers, chemists must know how much reactant they need to make a certain amount of product. Determining the quantities of reactants and products in a reaction requires a balanced chemical equation.
12.1 Using Everyday Equations • Using Everyday Equations • How is a balanced equation like a recipe?
12.1 Using Everyday Equations • A balanced chemical equation provides the same kind of quantitative information that a recipe does.
12.1 Using Everyday Equations • An equation can represent the manufacturing of a single tricycle.
12.1 Using Balanced Chemical Equations • Using Balanced Chemical Equations • How do chemists use balanced chemical equations?
12.1 Using Balanced Chemical Equations • Chemists use balanced chemical equations as a basis to calculate how much reactant is needed or product is formed in a reaction. • The calculation of quantities in chemical reactions is a subject of chemistry called stoichiometry.
12.1 Interpreting Chemical Equations • Interpreting Chemical Equations • In terms of what quantities can you interpret a balanced chemical equation?
12.1 Interpreting Chemical Equations • A balanced chemical equation can be interpreted in terms of different quantities, including numbers of atoms, molecules, or moles; mass; and volume.
12.1 Interpreting Chemical Equations • Number of Atoms
12.1 Interpreting Chemical Equations • Number of Molecules
12.1 Interpreting Chemical Equations • Moles
12.1 Interpreting Chemical Equations • Mass
12.1 Interpreting Chemical Equations • Volume
12.1 Interpreting Chemical Equations
12.1 Mass Conservation in Chemical Reactions • Mass Conservation in Chemical Reactions • What quantities are conserved in every chemical reaction?
12.1 Mass Conservation in Chemical Reactions • Mass and atoms are conserved in every chemical reaction.
A reaction that produces iron metal from iron ore is shown below. • Fe2O3•H2O(s) + 3CO(g) 2Fe(s) + 3CO2(g) + H2O(g) • In this equation, the volume of gas at STP that reacts and the volume of gas at STP produced will be • 3 L and 4 L. • 67.2 L and 89.6 L. • 67.2 L and 67.2 L • 3 L and 3 L
12.1 Section Quiz. • What is conserved in the reaction shown below? • H2(g) + Cl2(g) 2HCl(g) • only mass • only mass and number of moles • only mass, number of moles, and number of molecules • mass, number of moles, number of molecules, and volume