[molemole]

I am working on a lab that involves the preparation of 2 solutions (100.00mL of each).
I am preparing SolutionA: Buffer containing 0.060M acetic acid/.060M acetate ion.
                    Solution B: Buffer containing 0.060M ammonia/0.060M ammonium ion.
I am provided with 3 additional solutions
                    Solution C: 0.030M acetic acid/0.0030M acetate buffer
                    Solution D: 0.060M acetic acid
                    Solution E: 0.060M NaCl
Now my problem is I have to calculate the grams of salt, and volume of acid or base needed to make buffer solutions A and B. This has me very confused. Any help would be appreciated. Thanks.

[renge ishyo]

Here's some help for solution A (solution B is pretty much the same process). First you need to calculate how much *total* acetate/acetic acid you need to add to make your solution. This is the sum of the required amounts for acetic acid and acetate combined or  0.060M + 0.060M = 0.120 M sodium acetate that you will add. From here you can multiply this by 100x10^-3L to get moles and convert from moles to the amount of sodium acetate in grams that you need to dissolve to make your solution.

Step 2: Next you need to use the Hunderson Hasselbach equation to figure out the desired pH for a solution consisting of .060M acetic acid ([HA]) and .060M acetate [A-]. Use the published pKa for acetic acid in the equation to calculate the needed pH for your solution (it shouldn't take much calculation because the concentrations of [HA] and [A-] are equal...). Then add concentrated acid dropwise to get this solution to the desired pH, and the solution will be all set and ready to go.