Question

Calculate the pH of buffer solution containing 0.05 M NaF per litre and 0.015 M HF
per litre. [Ka = 7.2 × 10-4
for HF]

Answer 1

here is your answer

see the attachment.

Answer 2

Answer:

3.6655

Explanation:

To calculate the pH of this buffer solution, luckily we do not need to make an ICE table!

We can by using the Henderson-Hasselbach equation:

pH = pKa + log( [conc. base]/[conc. acid])

Keep in mind: pKa = -log(Ka)

In this problem HF acts as the acid and NaF acts as the base.

So,

pH = -log(7.2 x 10^-4) + log([0.05]/[0.015])

and if you plug this into your calculator you will get

3.6655