How much buffer do you want? The problem doesn't say; if you can choose a volume, say choose 500 mL. Then let x = mL base and 500-x = mL acid, then in the HH equation it becomes
4.0 = pKa + log (0.1*x)/[(500-x)*0.1] and solve for x = volume of the NaF and 500-x is volume of HF. Should work ok; if 500 is not what you want substitute another number for that.
How many millilitres of a 0.1 M solution of NaF and of 0.1 M solution of HF
must be mixed to obtain 1L of buffer at pH = 4? Ka = 6.7 × 10-4
Currently I am quite confident with using the henderson and Hasselbalch equation but this question has left me stumped...
Any help with the method of working this out would be greatly appreciated...
1 answer
1 answer