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A laboratory assistant is asked to prepare a buffer solution with a pH of 7.10 using acetic acid (CH3COOH) and sodium acetate (NaCH3COO). If the laboratory assistant has 250 mL of 0.20 M acetic acid, how many grams of NaCH3COO will be needed to make the buffer solution?

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To solve this problem, we will use the Henderson-Hasselbalch equation:pH = pKa + log  [A-]/[HA] where pH is the desired pH of the buffer solution, pKa is the acid dissociation constant for acetic acid, [A-] is the concentration of the conjugate base  sodium acetate , and [HA] is the concentration of the weak acid  acetic acid .The pKa of acetic acid is 4.74. We are given the desired pH  7.10  and the concentration of acetic acid  0.20 M . We can now solve for the concentration of sodium acetate:7.10 = 4.74 + log  [NaCH3COO]/[CH3COOH] 2.36 = log  [NaCH3COO]/0.20 10^2.36 = [NaCH3COO]/0.20229.09 = [NaCH3COO]/0.20[NaCH3COO] = 45.82 MNow, we need to find the number of moles of sodium acetate needed for the 250 mL buffer solution:moles of NaCH3COO = Molarity  Volume  in L moles of NaCH3COO = 45.82  0.250moles of NaCH3COO = 11.455Finally, we need to convert moles of sodium acetate to grams. The molar mass of NaCH3COO is approximately 82.03 g/mol:grams of NaCH3COO = moles  molar massgrams of NaCH3COO = 11.455  82.03grams of NaCH3COO  939.56 gTherefore, the laboratory assistant will need approximately 939.56 grams of sodium acetate to make the buffer solution with a pH of 7.10.

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