Science Fair Projects World

pH and Buffer Solutions


Study the properties of buffer solutions and how they resist changes in pH when acids or bases are added.


  • Buffer solutions (e.g., phosphate buffer)
  • pH meter or pH test strips
  • Hydrochloric acid (HCl)
  • Sodium hydroxide (NaOH)
  • Beakers
  • Dropper
  • Notebook for observations


  1. Measure and record the initial pH of the buffer solution using a pH meter or test strips.
  2. Add small amounts of hydrochloric acid (HCl) to the buffer solution and stir gently.
  3. Measure and record the pH after each addition.
  4. Repeat the process using sodium hydroxide (NaOH) instead of HCl.
  5. Observe and record how the pH changes compared to a solution without a buffer.
  6. Analyze the data to understand the buffering capacity of the solution.