Calculate the pH of a buffer consisting of 0.50 M HF and 0.45 F-
a) before
b) after addition of 0.40 g of NaOH to 1.0 L of the buffer
( Ka of HF = 6.8x10-4)

I understand the first part but I'm having difficulty with the second. Any help greatly appreciated!

Question

Calculate the pH of a buffer consisting of 0.50 M HF and 0.45 F- 
a) before
b) after addition of 0.40 g of NaOH to 1.0 L of the buffer 
( Ka of HF = 6.8x10-4)

I understand the first part but I'm having difficulty with the second. Any help greatly appreciated!

vincent-lyon.fr · Answer

Tip: write chemical equation of reaction between OH- and HF. Imagine the solution is 1 litre,  then work out the new amounts in solution after reaction.