The pH of acids and bases is based on the concentration of hydrogen ions {H+}. The pH scale goes from 0 - 14. A neutral solution has a pH of 7. Pure water has a pH of 7. The pH is the negative log of the hydrogen ion concentration: pH = -log[H+}. The concentration is given as the Molarity (M). Strong acids dissociate completely. In strong acids the pH can be determined from the molarity as the [H+]. In weak acids the molarity of the acid may not be used to calculate the pH, since not all of the H+ dissociate from the acid. In order to calculate the pH of a weak acid, the dissociation constant must be known.

1. 1ml or 10 ml pipette
2. 100ml graduated cylinder
3. .10 M HCl
4. .10 M KOH
5. .10 M CH₃COOH
6. pH paper
7. Litmus paper

1. Using blue and red litmus paper, measure the pH of .10 M HCl, .10 M KOH, and .10 M CH3C00H.
2. Measure 1.0 ml HCl and place in 100 ml graduated cylander.
3. Add distilled water to 100 ml.
4. Measure the pH using litmus and pH paper.
5. Calcualte the pH using the Molarity.
6. Repeate these steps using the .10 M KOH. Make sure your glassware is clean.
7. Make a table to record all of your results.

1. What is the pH of the diluted HCl? Show work for calculations
2. What is the pH of the diluted K)H? Show work for calculations.

1. What is the pH of the .10 M CH3C00H. I it different from the .10 M HCl? Why?
2. Describe what you would due to make a solution with a pH of 5 from a solution of pH .10 HCL