Please be detailed. Thanks What is the pH of a buffer prepared by adding 0.708 m
ID: 824784 • Letter: P
Question
Please be detailed. Thanks What is the pH of a buffer prepared by adding 0.708mol of the weak acid HA to 0.609mol of NaAin 2.00 L of solution? The dissociation constant Ka of HA is 5.66 Please be detailed. Thanks What is the pH of a buffer prepared by adding 0.708mol of the weak acid HA to 0.609mol of NaAin 2.00 L of solution? The dissociation constant Ka of HA is 5.66 Please be detailed. Thanks What is the pH of a buffer prepared by adding 0.708mol of the weak acid HA to 0.609mol of NaAin 2.00 L of solution? The dissociation constant Ka of HA is 5.66Explanation / Answer
[HA] = 0.708/ 2.00 = 0.354 M
[A-] = 0.609/2.00 =0.305 M
pKa = 6.25
pH = 6.25 + log 0.305 / 0.354 =6.19
A- + H+ >> HA
moles A- = 0.609 - 0.150 =0.459
[A-]= 0.459/ 2.00 =0.230 M
moles HA = 0.708 + 0.150 =0.858
[HA] = 0.858/2.00 = 0.429 M
pH = 6.25 + log 0.230/0.429 = 5.98
HA + OH- >> A- + H2O
moles HA = 0.708 - 0.195 =0.513
[HA]= 0.513/2.00 =0.257 M
moles A- = 0.609 + 0.195 =0.804
[A-]= 0.804/2.00 = 0.402 M
pH = 6.25 + log 0.402/0.257 =6.44