C Buffer Capacity ls A Mea x learning.com/ibiscms/mod/ibis/view.php?id 3016485 s
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C Buffer Capacity ls A Mea x learning.com/ibiscms/mod/ibis/view.php?id 3016485 score 012117/2016 10:55 PM A 5/10 Gradebook Print Calculator Periodic Table K incorrect Question 5 of 8 incorrect Map Sapling Learning Po Gra Buffer capacity is a measure of a buffer solution's resistance to changes in pH as strong acid or base is added. Des suppose that you have 105 mL of a buffer that is 0.360 Min both formic acid (HCooH) and its Polic buffer base the maximum volume of 0.410 M HCl that can be added to the before its buffering capacity is lost. You c You ca up on a ml. You can you get There is O eTextbo o Help With O Web Help O Technical si Previous eve Up View Solution Try Again Next 1Exit F11Explanation / Answer
pH of buffer = pka + log(salt/acid)
total no of mole of buffer = M*V = 0.105*0.36 = 0.0378 mole
no of mole of H-COOH = x mole
no of mole of H-COONa = 0.0378-x mole
pka of formicacid = 3.75
pH of buffer = 3.75+log((0.0378-x)/x)
if pH = pka , buffer capacity is maximum = 3.75
3.75 = 3.75 + log((0.0378-x)/x)
no of mole of H-COOH = x = 0.0189 mole
no of mole of H-COONa = 0.0378 - 0.0189 = 0.0189 mole
maximum buffer range , (pka+1) to (pka-1)
addition of HCl decreases the pH.
2.75 = 3.75+log((0.0189-x)/(0.0189+x))
x = no of mole of HCl added = 0.0155 mole
volume of HCl added = n/M = 0.0155/0.41 = 0.0378 L
= 37.8 ml
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