If you were given a solution that has a pH of 8.5, what would be its concentration of protons? What is the difference in proton concentration between this solution and one that has a pH of 7?

Verified step by step guidance

1. Understand the relationship between pH and proton concentration: pH is defined as the negative logarithm (base 10) of the hydrogen ion concentration. Mathematically, it is represented as pH = -log10[H+], where [H+] is the concentration of hydrogen ions in moles per liter.
2. Calculate the proton concentration for the solution with pH 8.5: Use the formula [H+] = 10^(-pH). Substituting the given pH, [H+] = 10^(-8.5) = 3.16 x 10^-9 M.
3. Calculate the proton concentration for the solution with pH 7: Similarly, use the formula [H+] = 10^(-pH). For pH 7, [H+] = 10^(-7) = 1 x 10^-7 M.
4. Determine the difference in proton concentration between the two solutions: Subtract the proton concentration of the pH 8.5 solution from that of the pH 7 solution. Difference = 1 x 10^-7 M - 3.16 x 10^-9 M = 9.684 x 10^-8 M.
5. Interpret the result: The solution with pH 7 has a higher proton concentration compared to the solution with pH 8.5. The difference in proton concentration is 9.684 x 10^-8 M, indicating that the pH 7 solution is more acidic.

Key Concepts

pH Scale

The pH scale measures the acidity or basicity of a solution, ranging from 0 to 14. A pH of 7 is considered neutral, values below 7 indicate acidity, and values above 7 indicate alkalinity. Each unit change in pH represents a tenfold change in hydrogen ion concentration, making it a logarithmic scale.

Proton Concentration

Proton concentration in a solution is often expressed in terms of molarity, specifically as [H+]. The relationship between pH and proton concentration is given by the formula [H+] = 10^(-pH). Therefore, a higher pH corresponds to a lower concentration of protons, while a lower pH indicates a higher concentration.

Calculating Differences in Proton Concentration

To find the difference in proton concentration between two solutions with different pH values, one can calculate the [H+] for each pH using the formula mentioned above. For example, a solution with pH 8.5 has a lower proton concentration than one with pH 7, and the difference can be quantified by subtracting the two concentrations.