# Pre-laboratory Question 1 The pKa of acetic acid is 47 What...

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Characteristics of a Buffered Solution Pre-laboratory Question 1. The pKa of acetic acid is 4.7. What is the buffering range of this acid and its conjugate base? Explain your answer.
2. Calculate the volume of 6 M acetic acid needed to prepare 100 mL of a 0.10 M acetic acid (CH 3 COOH) solution.
3. Calculate the mass of sodium acetate (CH 3 COONa) required to prepare 50 mL of a 0.10 M sodium acetate solution.
4. Calculate the volume of 1 M sodium hydroxide (NaOH) needed to prepare 10 mL of a 0.10 M sodium hydroxide solution.
5. Calculate the volume of 1 M hydrochloric acid (HCl) needed to prepare 10 mL of a 0.10 M hydrochloric acid solution.
6. Determine the volumes of 0.10 M CH 3 COOH and 0.10 M CH 3 COONa required to prepare 10 mL of the following pH buffers. (Note: the pK a of CH 3 COOH =4.7) 1 ©2014, Carolina Biological Supply Company
Characteristics of a Buffered Solution a. pH 3.7 3.7 = 4.7 + log (base)/(acid) log (base) / (acid) = -10 = log (10^-10) .10 M*Vb / .10M*Va = 10^-10 Vb/Va = 10^-10 Vb + Va = 10 mL Va = 1/(1+10^-10) * 10 mL = 9.99 = 10 mL