[Pomum]

Hi,

A buffer solution can be prepared by adding which of the following to 50cm³ of 0.10 mol dm^-3 CH₃COOH(aq)?

I. 50cm³ of 0.10 mol dm^-3 CH₃COONa(aq)
II. 25cm³ of 0.10 mol dm^-3 NaOH(aq)
III. 50cm³ of 0.10 mol dm^-3 NaOH(aq)

A. I only
B. I and II only
C. II and III only
D. I, II and III

The actual answer is B.

I understand why 'I' is correct, but why is 'II' correct too? And then why not 'III'?

Thanks for any help,
Pomum

[EierVonSatan]

In II some of the acid is converted into the conjugate base by NaOH

In III all of the acid is converted into the conjugate base by NaOH