A buffer system (pKa = 5) is composed of 0.1 moles of weak acid and 0.05 moles of the conjugate base. What is the pH of the system after the addition of 0.07 moles of a strong base?
after adding strong acid following reaction takes place
strong base + weak acid -----------> conjugate base + water
after strong acid added
assume total volume = 1.0 L
moles of conjugate base = 0.05 + 0.07 = 0.12
moles of weak acid = 0.1 - 0.07 = 0.03
[weak acid] = 0.03 M
[conjugate base] = 0.12 M
for acidic buffer
pH = pKa + log [conjugate base] / [weak acid]
pH = 5.0 + log [0.12] / [0.03]
pH = 5.60
A buffer system (pKa = 5) is composed of 0.1 moles of weak acid and 0.05...
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A buffer solution is made by adding 1.00 M weak acid (pKa = 4.45) to 1.25 M solution of its conjugate base to make 100 mL of buffer solution. Calculate the pH after 75.0 mL of 0.725 M strong acid has been added.
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