How to Determine the pH of a Buffer Solution

Chemical and biological reactions always contain hydronium ions within the solutions involved in each process. Any change in the concentration of these ions can cause drastic changes in all steps of the process. Hydronium ions are generally measured as the hydrogen ion's negative logarithm. This also refers to the pH concentration. Laboratory tests always use buffers to maintain the pH of the chemical substances involved in the test or reaction. They use substances (such as blood samples) that are stored in special containers under specific environmental conditions, such as temperature, pressure and pH concentration.

Things You'll Need

• Sample of buffer solution pH paper Medicine dropper Test tube Watch glass/plain white paper pH meter (optional)

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Instructions

Guide to Measure the pH of a Buffer

• 1

  Prepare a sample of your buffer solution, and place it in a clean, dry test tube or beaker.

• 2

  Prepare your pH paper indicator by placing one strip or sheet in a dry and clean watch glass or on top of a dry, plain white paper. Placing the pH paper indicator against a transparent glass or white background helps determine a more accurate pH, because you can easily see the change in color.

• 3

  Use the medicine dropper to slowly drop the buffer solution onto your paper indicator. The organic dyes inside the paper indicator will react to your buffer, causing a change in color.

• 4

  Compare the new color of the paper to your pH standard chart ,and record the pH concentration that matches it.

• 5

  If you have a pH meter, check the concentration by inserting the electrode into the flask containing your buffer solution, and it will automatically indicate the accurate pH concentration.