The ph of a 0.25 m aqueous solution of hydrofluoric acid, hf, at 25.0 °c is 2.03. what is the value of ka for hf?
6.0 × 10-5
3.5 × 10-4
1.1 × 10-9
2.0 × 10-9
none of the above

Answer : The correct option is,

Solution : Given,

pH = 2.03

Concentration of HF = 0.25 M

First we have to calculate the concentration of ion.

Now we have to calculate the value of for HF.

The equilibrium reaction will be

Concentration of = Concentration of =

The expression for for HF will be,

Therefore, the value of for HF is,

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.