Calculate pH from OH.
Understand the Problem
The question is asking how to calculate the pH from the concentration of hydroxide ions (OH-). This involves using the relationship between pH and pOH, where pH = 14 - pOH. To find pH, we first need to determine pOH from the hydroxide ion concentration and then subtract that value from 14.
Answer
The pH can be calculated as $ \text{pH} = 14 + \log [\text{OH}^-] $.
Answer for screen readers
The final answer for pH, given the concentration of hydroxide ions, can be calculated using the steps provided.
Steps to Solve
- Calculate the pOH from [OH⁻]
To find pOH, we use the formula: $$ \text{pOH} = -\log [\text{OH}^-] $$ where $[\text{OH}^-]$ is the concentration of hydroxide ions.
- Calculate the pH from pOH
Once we have pOH, we can find pH using the relationship: $$ \text{pH} = 14 - \text{pOH} $$ This gives us the final pH of the solution.
- Example of the calculations
If, for example, the concentration of hydroxide ions is $0.01 , \text{M}$, we would first calculate: $$ \text{pOH} = -\log(0.01) = 2 $$ Then calculate pH: $$ \text{pH} = 14 - 2 = 12 $$
The final answer for pH, given the concentration of hydroxide ions, can be calculated using the steps provided.
More Information
The pH scale ranges from 0 to 14, where a pH below 7 is acidic, a pH of 7 is neutral, and a pH above 7 is basic. Understanding pH is essential in various fields, including chemistry, biology, and environmental science.
Tips
- Forgetting to take the negative logarithm when calculating pOH can lead to incorrect results.
- Confusing the relationship between pH and pOH; remember, $ \text{pH} + \text{pOH} = 14 $.