Beaker #1: Unbuffered Solution
1. Place 50 ml of deionized water in a beaker and add 6 drops of universal pH indicator. Note the color and record.
2. Add 3 drops of 1.0 M HCl. Note the new color and record the pH.
3. Save this beaker & solution for comparison to situation #2.
Beaker #2: Buffered System
1. Make a buffer solution in a new beaker. Do this by putting 50 ml of 0.1 M NaHCO3 solution in the beaker and blowing exhaled breath into the solution for at least 2 minutes.
2. Add 6 drops of universal pH indicator. Note the color and record the pH.
3. Add 3 drops of 1.0 M HCl as you did above and note the color and record the pH.
4. Continue to add acid drop by drop, counting the drops (swirl to mix) until the color matches the unbuffered solution from step 2 in situation #1. How many drops did you use?Record.