OUTLINE
3-1 Chemical Equations
3-2 Calculations Based on Chemical
Equations
3-3 The Limiting Reactant Concept
3-4 Percent Yields from Chemical
Reactions
3-5 Sequential Reactions
3-6 Concentrations of Solutions
3-7 Dilution of Solutions
3-8 Using Solutions in Chemical
Reactions
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OBJECTIVES
After you have studied this chapter, you should be able to
- Write balanced chemical equations to describe chemical reactions
- Interpret balanced chemical equations to calculate the molesof reactants and products
involved in each of the reactions - Interpret balanced chemical equations to calculate the massesof reactants and products
involved in each of the reactions - Determine which reactant is the limiting reactant in reactions
- Use the limiting reactant concept in calculations recording chemical equations
- Compare the amount of substance actually formed in a reaction (actual yield) with the
predicted amount (theoretical yield), and determine the percent yield - Work with sequential reactions
- Use the terminology of solutions — solute, solvent, concentration
- Calculate concentrations of solutions when they are diluted
- Carry out calculations related to the use of solutions in chemical reactions
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n Chapter 2 we studied composition stoichiometry, the quantitative relationships
among elements in compounds. In this chapter as we study reaction stoichiometry—
the quantitative relationships among substances as they participate in chemical reac-
tions—we ask several important questions. Howcan we describe the reaction of one sub-
stance with another? How muchof one substance reacts with a given amount of another
substance? Which reactantdetermines the amounts of products formed in a chemical re-
action? Howcan we describe reactions in aqueous solutions?
Whether we are concerned with describing a reaction used in a chemical analysis, one
used industrially in the production of a plastic, or one that occurs during metabolism in
the body, we must describe it accurately. Chemical equations represent a very precise, yet
a very versatile, language that describes chemical changes. We begin our study by exam-
ining chemical equations.
Methane, CH 4 , is the main component of natural gas.
Steel wool burns in pure oxygen
gas.
4Fe3O 2 88n2Fe 2 O 3