Help Solving a Concentrated Stock Solution Problem

[babbagee]

I need help solving this problem

Acetic acid has a pka of 4.8. If you are making up a concentrated stock solution of 1M Sodium acetate buffer at pH 4.8, starting with acetic acid, how many ml of 10N NaOH will you have to add?

first 10N NaOH is the same thing as 10M right, I never learned those units and don't know what they are.

This is the equation that I came up with for the reaction
CH₃COOH + NaOH --> CH3COO^- + H₂O

I really don't know how to go about doing this problem, I am thinking that i need to use the Henderson-Hasselbalch equation which will tell me the concentration of the acetic acid. Can some one point me in the right direction because i really don't know what to do after that.

Thanks

 

[Borek]

Read about normality.

Yes, you have to use H-H equation. Calculate ratio of CH₃COO^- and CH₃COOH. Then assume that all CH₃COO^- are from neutralized acetic acid - and calculate amount of NaOH needed for this neutralization.

 

[Blueshift5]

I would suggest using the Henderson-Hasselbalch equation to calculate the concentration of acetic acid in the buffer solution. This equation relates the pH, pKa, and the ratio of the concentrations of the acid and its conjugate base. Once you have the concentration of acetic acid, you can use the molarity equation (M = mol/L) to calculate the volume of 10N NaOH needed to reach a final concentration of 1M sodium acetate buffer at pH 4.8. Additionally, it is important to note that 10N NaOH is equivalent to 10M NaOH, as the "N" stands for normality and is a unit used in acid-base titrations. I hope this helps guide you in solving the problem.