The formula you provided calculates the percent change in pH based on the difference between the pH at 5 drops and the pH at 0 drops. Here's how you can use the formula:
1. Determine the pH at 5 drops and the pH at 0 drops.
Let's say the pH at 5 drops is 4 and the pH at 0 drops is 7.
2. Plug the values into the formula:
Percent Change of pH = 100% × (pH at 5 drops - pH at 0 drops) / pH at 0 drops
Percent Change of pH = 100% × (4 - 7) / 7
3. Calculate the numerator:
4 - 7 = -3
4. Calculate the denominator:
Percent Change of pH = 100% × (-3) / 7
5. Calculate the percent change:
Percent Change of pH = -300% / 7
Therefore, the percent change in pH from 0 drops to 5 drops is approximately -42.86%.