SBI4U
Name: ___________________________________
ACIDS, BASES AND BUFFERS LAB
Procedure:
1. Read over the procedure and prepare an appropriate Observation Table.
2. Clean 5 test tubes thoroughly. Label them A, B, C, D, E and place them in a test tube stand.
3. Make the buffer solution:
Measure 15 mL of 0.1 M acetic acid solution into a small beaker. Add 0.10 g of sodium acetate
to the beaker and swirl the mixture until the solid dissolves.
4. Measure 5 mL of distilled water into test tube A and E only.
5. Divide the buffer solution equally, 5 mL into test tubes B, C and D.
6. Obtain a small piece of pH paper. Use a clean glass stirring rod to add a drop of solution A to the pH
paper and record the initial pH of solution A. Continue for the rest of the solutions (B-E) washing and
drying the stirring rod after each use.
7. To test tubes A and B, add 5 mL of 0.1 M hydrochloric acid, gently swirl the solution, and test the pH
again.
8. To test tubes D and E, add 5 mL of 0.1 M sodium hydroxide, gently swirl the solution, and test the pH
again.
Questions:
1. What pH range is considered to be:
a) acidic?
b) basic?
c) neutral?
2. Compare the initial and final pH in test tube A and B. What was the effect of the buffer?
3. Compare the initial and final pH in test tube D and E. What was the effect of the buffer?
4. What was the purpose of test tube C?
5. Write the reaction for the bicarbonate-carbon dioxide buffer system that operates in humans and briefly
explain how it works in the case of a patient experiencing respiratory or metabolic acidosis (too much
acid).
6. Submit an abstract for this mini lab.