I'm trying to calculate the pH of a 1.0M solution of Sodium Acetate given that Ka = 1.8 x 10 ^-5. The only formula we have been given is pH = pKa +...

I'm trying to calculate the pH of a 1.0M solution of Sodium Acetate given that Ka = 1.8 x 10 ^-5.

The only formula we have been given is pH = pKa + log [A-]/[HA], which gives 4.74 + log 1 (assuming 1:1 dissociation) which = 4.74.

A tutor used the formula....pH = 1/2[pKw +pKa + logC] which gives an answer of 9.37. We have not

been exposed to this formula so I am thinking it can be solved with the above formula.

Can I use to first formula to get the correct answer? If not, why not?