What is the pH of the final solution? ?
A buffer solution is made by adding 75.0 g sodium acetate (NaC2H3O2) to 500.0 mL of a
0.64 M solution of acetic acid (HC2H3O2). What is the pH of the final solution? Assume no volume change.
- jacob sLv 74 months ago
Moles = mass/molar mass
Moles of NaC2H3O2 = 75/82=0.88 mol NaC2H3O2
Moraity = moles/volume
moles = molarity*volume(liter)
Moles of Acetic acid = 0.64M*(500/1000)L=0.32 mol
pKa of acetic acid = .
According to Henderson Hasselbalch Equation
pH = pka + log[salt]/[acid]
- ChemTeamLv 74 months ago
You need to know the molarity of the NaAc:
MV = mass / molar mass
(x) (0.5000 L) = 75.0 g / 82.0337 g/mol
x = 1.82852 M (keep some guard digits)
Now, use the Henderson-Hasselbalch equation:
pH = pKa + log [base / acid]
pH = 4.752 + log [1.82852 / 0.64]
pH = 4.752 + 0.456
pH = 5.208 (round off more as you see fit)