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Concept:

# Problem: Calculate the pH of a solution prepared by mixing 50 mL of a 0.10 M solution of HF with 25 mL of a 0.20 M solution of NaF. pKa of HF is 3.14.A) 5.83B) 12.00C) 3.14D) 7.35E) 10.80

###### FREE Expert Solution

For this problem, we have to calculate the pH when 49.5 mL of 0.335 M NaA is mixed with 30.6 mL of 0.120 M HCl.

• HF and NaF are conjugate pairs, hence we can use Henderson-Hasselbach equation to calculate the pH
• To do so, follow these steps

Step 1. Find the moles of Fand HF

Step 2Calculate the pH using HH equation

(1) Moles of Awill be calculated as:

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###### Problem Details

Calculate the pH of a solution prepared by mixing 50 mL of a 0.10 M solution of HF with 25 mL of a 0.20 M solution of NaF. pKa of HF is 3.14.

A) 5.83

B) 12.00

C) 3.14

D) 7.35

E) 10.80