What is the pH of a solution prepared by mixing 24,6g sodium acetate and 50mL of 2.5 M acetic acid in a 500mL flask and filling it to volume?
If possible please list steps... Thank You
If possible please list steps... Thank You
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First, you want the moles of sodium acetate, which i will abbreviate as A-. Acetic acid corresponds to HA.
(24.6 g A-) * (1 mol A- / 82.03 g A-) = 0.2998 mol A- (I'm keeping an extra sig fig so I won't have any rounding errors).
Now you want the moles of HA:
(2.5 mol/L HA) * 0.050L HA = 0.125 mol HA
Now you can just plug in those values into the Henderson-Hasselbach equation:
pH = pKa + log ([A-]/[HA])
pH = 4.756 + log (0.2998/0.125)
pH = 5.1359
pH = 5.14
(24.6 g A-) * (1 mol A- / 82.03 g A-) = 0.2998 mol A- (I'm keeping an extra sig fig so I won't have any rounding errors).
Now you want the moles of HA:
(2.5 mol/L HA) * 0.050L HA = 0.125 mol HA
Now you can just plug in those values into the Henderson-Hasselbach equation:
pH = pKa + log ([A-]/[HA])
pH = 4.756 + log (0.2998/0.125)
pH = 5.1359
pH = 5.14
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first find the moles of sodium acetate
MM of sodium acetate=82.04 g/mol
now divide your grams of sodium acetate used by the MM
(24.60g)*(one mole/82.04g)=0.29985 mol
now find the moles of acetic acid
0.050L*2.5M=0.125 mol
now divide each of them by the new volume of 500mL
sodium acetate=0.29985 mol/0.500L=0.5997 M
acetic acid=0.250M
now use the Henderson Hasselbalch equation to fnd pH Ka of acetic acid = 1.8E-5 pKa=4.7447
pH=pKa+log([base]/[acid])
pH=4.7447+log(0.5997M/0.250M)
pH=5.12
you could also just use moles right off the back then your equation would look like this
pH=4.7447+log(0.29985mol/0.125mol)
pH=5.12
either way works but using moles is a lot easier and faster
MM of sodium acetate=82.04 g/mol
now divide your grams of sodium acetate used by the MM
(24.60g)*(one mole/82.04g)=0.29985 mol
now find the moles of acetic acid
0.050L*2.5M=0.125 mol
now divide each of them by the new volume of 500mL
sodium acetate=0.29985 mol/0.500L=0.5997 M
acetic acid=0.250M
now use the Henderson Hasselbalch equation to fnd pH Ka of acetic acid = 1.8E-5 pKa=4.7447
pH=pKa+log([base]/[acid])
pH=4.7447+log(0.5997M/0.250M)
pH=5.12
you could also just use moles right off the back then your equation would look like this
pH=4.7447+log(0.29985mol/0.125mol)
pH=5.12
either way works but using moles is a lot easier and faster