pH Values

1. pH Values

2. Admit Slip • Which substance has the highest concentration of hydrogen ions (H+), an acidic solution or a basic solution ? • Which of the following substances has the highest concentration of hydrogen ions in solution? • A. bleach – pH 13 • B. water – pH 7 • C. tomato juice – pH 4 • D. vinegar – pH 3 Unit IV • Investigation IV-X

3. Agenda • Admit Slip • Notes • Worksheet • Exit Slip • Homework : Look up the definition of the chemistry term “buffer”

4. Objectives • Students will be able to: • Explain the connection between pH and H+ concentration. • Convert between pH value and H+ concentration • Write a neutralization reaction. • Identify acids, bases, and salts.

5. The Big Question Where does the pH number come from? Unit IV • Investigation IV-X

6. The pH of a solution is decided by the concentration of H+ ions in the solution. The concentration of H+ ions[H+]is equal to 10 raised to the negative of the pH value. So, if the pH is 2, then the H+ ion concentration [H+] is 10-2 M. If the pH is 9, then [H+] = 10-9 M The pH and concentration of H+ have an inverse relationship. The higher the concentration of H+ ions, the lower the pH. . pH Values 5 / 6 /13 Unit IV • Investigation IV-X

7. To convert between a power of 10n and a decimal, the number of zeros after the decimal is equal to 1 less than the number n.The zeros are then followed by a 1. Powers of 10 and decimal equivalents Unit IV • Investigation IV-X

8. Classwork • Classwork including Exit Slip is due at :

9. Exit Slip • Is HF an acid or a base? • What is the pH of a solution of 0.1 M HF? • What is the [H+] of a solution with a pH of 5? Write it as a power of 10 and as a decimal.