# Question #6c230

##### 2 Answers

The total volume of the buffer represents the sum of the volumes of the acetic acid and sodium acetate solutions. I'll use

**(1)**

This will represent your first equation (notice that I've used liters instead of mililiters).

Since you're dealing with a buffer, use the **Henderson-Hasselbalch equation** to try and find another relationship between

Plug in the values you have for pH and

**(2)**

Now, the concentration of sodium acetate can be written as

The number of moles of sodium acetate can be found by using the initial concentration of

Likewise, the concentration of acetic acid can be written as

The number of moles of acetic acid will equal

Plug these values into equation **(2)** and you'll get

**(1)**

These values represent the volumes in liters for the sodium acetate and acetic acid solutions you need to mix to get this buffer.

Therefore, the volume of acetic acetic solution you need is

173.9 ml is required.

Because

Where

And

2 eqns, 2 unknowns.