Ch 4: Reactions

About This Chapter

Watch online video lessons to learn how chemical reactions and phase changes occur. Find out how atoms and the effects of temperature create new chemical substances or change the state of existing ones.

Reactions - Chapter Summary and Learning Objectives

This chapter is designed to help you understand what happens in a chemical reaction, the process by which atoms and molecules come together to form new chemical substances. These reactions are similar to what might happen during the cooking process and usually occur as a result of energy, pressure, temperature or time. Using clear and concise graphics and explanations, your instructor will show you how scientists use equations and symbols, such as arrows, letters and numbers, to identify the products or results of these reactions.

The second half of this chapter will provide you with information about phase changes, or the process by which temperature transforms substances into gases, liquids or solids. You'll also find out how donating or receiving ions from a chemical solution determines whether a solution is an acid or base. After you've finished watching the tutorials and taking the online self-assessment quizzes, you should be able to:

  • Understand why and how chemical reactions occur among atoms
  • Identify the main types of chemical reactions
  • Name the six categories of phase changes and explain how they occur
  • Understand how the pH test is used to classify acids and bases

Chemical Reactions and Balancing Chemical EquationsDefine a chemical reaction, and show how to balance a chemical equation.
Reactant Atoms and MoleculesUnderstand how reactant atoms and molecules interact to form substances with different chemical properties.
Phase Change: Evaporation, Condensation, Freezing, Melting, Sublimation and DepositionDescribe what happens when substances condense, evaporate, freeze and melt. Explain the processes of deposition and sublimation.
Acidic, Basic and Neutral SolutionsDetermine whether a solution is acidic, basic or neutral.

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