Calculating pH from Hydronium Concentration

Oct 13, 2025 by wbrum.org 70 views

pH is a measure of the concentration of hydrogen ions (H+) in a solution. It is an important concept in chemistry, as it helps us understand the acidity or basicity of a solution. In this article, we will explore the relationship between pH and hydronium concentration, and use this knowledge to determine the pH of a solution with a given hydronium concentration.

The pH Scale

The pH scale is a logarithmic scale that ranges from 0 to 14. A pH of 7 is considered neutral, while a pH less than 7 is acidic and a pH greater than 7 is basic. The pH scale is defined as:

pH = -log[H+]

where [H+] is the concentration of hydrogen ions in moles per liter (M).

Hydronium Concentration

Hydronium ions (H3O+) are a type of hydrogen ion that is commonly found in aqueous solutions. The concentration of hydronium ions is related to the pH of a solution by the following equation:

pH = -log[H3O+]

Calculating pH from Hydronium Concentration

To calculate the pH of a solution with a given hydronium concentration, we can use the equation above. Let's consider the solution with a hydronium concentration of 5.6 × 10^(-9) M.

pH = -log(5.6 × 10^(-9))

To solve this equation, we can use a calculator or a logarithmic table. The result is:

pH ≈ 8.25

Conclusion

In this article, we have explored the relationship between pH and hydronium concentration. We have used the equation pH = -log[H3O+] to calculate the pH of a solution with a given hydronium concentration. The result is a pH of approximately 8.25.

Answer

The correct answer is:

B. 8.25

Discussion

This problem is a classic example of how to calculate pH from hydronium concentration. It requires a basic understanding of the pH scale and the relationship between pH and hydronium concentration. The solution involves using the equation pH = -log[H3O+] to calculate the pH of the solution.

Additional Information

The pH scale is a logarithmic scale that ranges from 0 to 14.
A pH of 7 is considered neutral, while a pH less than 7 is acidic and a pH greater than 7 is basic.
Hydronium ions (H3O+) are a type of hydrogen ion that is commonly found in aqueous solutions.
The concentration of hydronium ions is related to the pH of a solution by the equation pH = -log[H3O+].

References

Atkins, P. W., & De Paula, J. (2010). Physical chemistry. Oxford University Press.
Brown, T. E., & LeMay, H. E. (2014). Chemistry: The Central Science. Pearson Education.

Q: What is the pH of a solution with a hydronium concentration of 1.0 × 10^(-7) M?

A: To calculate the pH of this solution, we can use the equation pH = -log[H3O+]. Plugging in the value of [H3O+] = 1.0 × 10^(-7) M, we get:

pH = -log(1.0 × 10^(-7)) pH ≈ 7.00

Q: What is the pH of a solution with a hydronium concentration of 5.0 × 10^(-6) M?

A: To calculate the pH of this solution, we can use the equation pH = -log[H3O+]. Plugging in the value of [H3O+] = 5.0 × 10^(-6) M, we get:

pH = -log(5.0 × 10^(-6)) pH ≈ 5.30

Q: What is the pH of a solution with a hydronium concentration of 2.5 × 10^(-5) M?

A: To calculate the pH of this solution, we can use the equation pH = -log[H3O+]. Plugging in the value of [H3O+] = 2.5 × 10^(-5) M, we get:

pH = -log(2.5 × 10^(-5)) pH ≈ 4.60

Q: How does the pH of a solution change when the hydronium concentration is increased?

A: When the hydronium concentration is increased, the pH of the solution decreases. This is because the equation pH = -log[H3O+] shows that pH is inversely proportional to the logarithm of the hydronium concentration.

Q: How does the pH of a solution change when the hydronium concentration is decreased?

A: When the hydronium concentration is decreased, the pH of the solution increases. This is because the equation pH = -log[H3O+] shows that pH is inversely proportional to the logarithm of the hydronium concentration.

Q: What is the relationship between pH and acidity?

A: The pH of a solution is related to its acidity. A solution with a pH less than 7 is acidic, while a solution with a pH greater than 7 is basic. The pH scale is a logarithmic scale that ranges from 0 to 14, with a pH of 7 being neutral.

Q: What is the relationship between pH and hydronium concentration?

A: The pH of a solution is related to its hydronium concentration. The equation pH = -log[H3O+] shows that pH is inversely proportional to the logarithm of the hydronium concentration.

Q: How can I calculate the pH of a solution with a given hydronium concentration?

A: To calculate the pH of a solution with a given hydronium concentration, you can use the equation pH = -log[H3O+]. This equation shows that pH is inversely proportional to the logarithm of the hydronium concentration.

Conclusion

In this article, we have answered some frequently asked questions about pH and hydronium concentration. These questions are based on the concepts discussed in the previous article, and are designed to help you better understand the relationship between pH and hydronium concentration. We hope that this article has been helpful in clarifying any confusion you may have had about these topics.