Question

"Calculate the pH during the titration of 20.00 mL of 0.1000 M HF(aq) with 0.2000 M NaOH(aq) after 9.4 mL of the base have been added. Ka of hydrofluoric acid

Answer 1

The answer is " 10.39"

Step-by-step explanation:

Calculating acid moles:

`= 0.02000 \ L * 0.1000 \ M \\\\= 0.002000`

Calculating NaOH moles:

`= 0.02012 \ L * 0.1000 \ M \\\\= 0.002012`

calculating excess in OH- Moles:

`= 0.002012 - 0.002000\\\\=0.000012`

calculating total volume:

`= 20.00 + 20.12\\\\ = 40.12 mL \\\\= 0.04012 L`

`[OH-]= \frac{0.000012} { 0.0472}`

`=0.00025 M`

`pOH = - \log 0.00025`

= 3.6

`pH = 14 - pOH`

= 10.39