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Biology: Semester I

Sections:

Introduction | Section 1 | Section 2

  Section Two:

Part 1 | Part 2 | Part 3 | Part 4 | Part 5 | Part 6

  

Biology: Chemistry of Life: Part Four

Acids and Bases

In any sample of water, a few water molecules break apart to form hydrogen (H+) and hydroxide (OH-) ions. Pure water has the same number (concentration) of H+ and OH- ions. Compounds that form hydrogen ions when dissolved in water are called acids. In contrast, compounds that reduce the concentration of hydrogen ions in a solution are referred to as bases.

Chemists have devised the pH scale to indicate the degree of acidity in a solution. The pH scale represents the concentration of H+ ions in a solution. The scale ranges between 0 and 14, with higher numbers being bases and lower numbers being acids.  

Look at the graphic showing the pH scale. How many of the items on this image are “bad” for you? What are their pH values?


Now go on to the next part. Next

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