Calculate The Ph of The Following Solutions 10 M Naoh
'/%3E%3Ccircle cx='48' cy='39' r='19' fill='%23f2c9a5'/%3E%3Cpath d='M27 35c3-16 39-17 42 2-8-8-27-9-42-2z' fill='%23374151'/%3E%3Cpath d='M21 86c5-24 49-28 56 0z' fill='%232563eb'/%3E%3Ccircle cx='41' cy='41' r='2' fill='%23111827'/%3E%3Ccircle cx='55' cy='41' r='2' fill='%23111827'/%3E%3Cpath d='M42 52c4 3 9 3 13 0' stroke='%2392400e' stroke-width='3' fill='none' stroke-linecap='round'/%3E%3C/svg%3E)
Reviewed by Calculator Editorial Team
Calculating the pH of a 10 M NaOH solution is a fundamental chemistry problem that demonstrates the behavior of strong bases. This guide provides a step-by-step method for determining the pH, explains the underlying principles, and includes a practical example.
How to Calculate the pH of 10 M NaOH
To calculate the pH of a 10 molar NaOH solution, follow these steps:
- Recognize that NaOH is a strong base that completely dissociates in water.
- Calculate the hydroxide ion concentration ([OH⁻]) using the molar concentration of NaOH.
- Use the relationship between [OH⁻] and pH to determine the solution's pH.
Key Formula
pH = 14 - pOH
pOH = -log[OH⁻]
Understanding Strong Base pH
Strong bases like NaOH completely dissociate in water, producing hydroxide ions (OH⁻). The pH of a strong base solution can be calculated using the hydroxide ion concentration.
The pH of a strong base solution is determined by the concentration of hydroxide ions it produces. For a 10 M NaOH solution, the hydroxide ion concentration is equal to the NaOH concentration because the base is fully dissociated.
Calculation Method
The calculation involves these steps:
- Determine the hydroxide ion concentration: [OH⁻] = [NaOH] = 10 M
- Calculate pOH: pOH = -log[OH⁻] = -log(10) = 1
- Calculate pH: pH = 14 - pOH = 14 - 1 = 13
Important Note
This calculation assumes the solution is dilute enough that the water autoionization can be neglected. For very concentrated solutions, more complex calculations may be needed.
Worked Example
Let's calculate the pH of a 10 M NaOH solution:
- Given: [NaOH] = 10 M
- Since NaOH is a strong base, [OH⁻] = [NaOH] = 10 M
- pOH = -log[OH⁻] = -log(10) = 1
- pH = 14 - pOH = 14 - 1 = 13
The pH of a 10 M NaOH solution is 13.
Frequently Asked Questions
Why is the pH of 10 M NaOH 13?
The pH is 13 because the hydroxide ion concentration is 10 M, resulting in pOH = 1 and pH = 13.
Does this calculation work for all concentrations of NaOH?
Yes, this calculation applies to any concentration of NaOH, assuming the solution is dilute enough that water autoionization is negligible.
What happens if the NaOH solution is very concentrated?
For very concentrated solutions, the water autoionization becomes significant, and more complex calculations may be needed.