Final answer:
To calculate the percent difference between two pH values, use the formula: 100 x absolute value of (first pH - second pH) / average of the pH values.
Step-by-step explanation:
To calculate the percent difference between two pH values, you can use the formula: 100 x absolute value of (first pH - second pH) / average of the pH values. In this case, the first pH value is 7.1 and the second pH value is 7.3. So the percent difference will be: 100 x |7.1 - 7.3| / ((7.1 + 7.3) / 2). Plugging in the values, we get: 100 x 0.2 / 7.2 = 2.78%.
Learn more about calculating percent difference between pH values