In this Acid-Base Titration, find the molarity of NaOH from the given values. Th
ID: 488810 • Letter: I
Question
In this Acid-Base Titration, find the molarity of NaOH from the given values. Then find the molarity of Acetic Acid from the given values. Show all calculations.
1. mass of KC8H5O4 : 0.497g
volume of (0.3M) NaOH solution added : 4.15mL
Molarity of NaOH : ____________
2. volume of vinegar : 10.00mL
volume of NaOH added : 11.55mL
Molarity of Acetic Acid : ___________
Mass percent of acetic acid (C2H4O2) in sample (assuming density of vinegar is 1.0g/mL) : ___________
If your standardized NaOH was used to titrate 20.00 mL of H2SO4, what concentration of H2SO4 would you determine if 24.66 mL of the NaOH solution was required by the titration? Give the balanced equation for this reaction.
Explanation / Answer
1)
Molarity of NaOH , as stated before is 0.3 M i.e. 0.3 mol of NaOH per liter
Q2
For the acetic acid:
mol of base = mol of acid
mol of base = MV = 0.3*11.55 = 3.465 mmol of OH-
so mol of H+ = 3.465 mmol
[Acid] = mmol/V = 3.465/10 = 0.3465 M
So
% mass = mass of aci d/ total Volume
mass of acid = mol*MW = (3.465 *10^-3)(60) = 0.2079 g of acid
% = 0.2079 /10 *100 = 2.079% is acetic acid
Q3.
mol of NaOH = MV = 0.3*24.66 = 7.398 mmol of NaOH
so
mmol of H+ = 7.398 mmol
2 mol of H+ per mol of H2SO$
so
H2SO4 = 1/2*7.398 = 3.699 mmol of H2SO4
M = mmol/mL = 3.699 / (20) = 0.18495M
H2SO4 + 2NaOH = Na2SO4 + 2H2O