A 0.02500 g sample of the diprotic acid malonic acid (H2C3H2O4)
is dissolved in water to...
A 0.02500 g sample of the diprotic acid malonic acid (H2C3H2O4)
is dissolved in water to yield a 2.00 L solution. What is the
resulting pH of the solution and the concentration of malonate ion
(C3H2O4^2-) at equilibruim?
Malonic acid (H2M) is a diprotic acid. You wish to prepare a
buffer of malonic acid (pKa1 = 2.847, pKa2= 5.696) with a final pH
of 2.90 but you only have disodium malonate (M2-) in your
laboratory shelf. You dissolve 100 mmol of this salt in 1 L of
water. Assume both dissociation processes are decoupled.
What is the initial pH of the solution? State any assumptions
you make.
How many equivalents of strong acid must you add to your...
A 425 mg sample of a weak diprotic acid is dissolved in enough
water to make 275.0 ml of solution. The pH of this solution is
3.08. A saturated solution of calcium hydroxide (Ksp=
1.3 x 10-6) is prepared by adding excess calcium
hydroxide to water and then removing the undissolved solid by
filtration. Enough of the calcium hydroxide solution is added to
the solution of the acid to reach the second equivalence point. The
pH at the second equivalence...
A 425 mg sample of a weak diprotic acid is dissolved in enough
water to make 275.0 ml of solution. The pH of this solution is
3.08. A saturated solution of calcium hydroxide (Ksp= 1.3 x 10^-6) is prepared by adding excess
calcium hydroxide to water and then removing the undissolved solid
by filtration. Enough of the calcium hydroxide solution is added to
the solution of the acid to reach the second equivalence point. The
pH at the second equivalence...
A 40.00 mL sample of 0.1000 M diprotic malonic acid is titrated
with 0.0900 M KOH. What volume KOH must be added to give a pH of
6.00 ? Ka1 = 1.42 × 10−3 and Ka2 = 2.01 × 10−6.
A 25.00 mL sample of 0.120 M of the diprotic malonic acid,
HOOC-CH2-COOH, was titrated with 0.250 M NaOH. If the following
results were obtained, calculate Ka1 and Ka2.
mL NaOH added: 5.00 6.00 10.00 12.00 15.00 18.00 20.00 24.00
pH: 2.68 2.83 3.53 4.26 5.21 5.69 6.00 9.24
A 0.1276 g sample of an unknown monoprotic acid was dissolved in
25.0 mL of water and titrated with 0.0633 M NaOH solution. The
volume of base required to bring the solution to the equivalence
point was 18.4 mL. (a) Calculate the molar mass of the acid. (b)
After 10.0 mL of base had been added during the titration, the pH
was determined to be 5.87. What is the Ka of the unknown acid? (10
points)
A 6.31 g sample of benzoic acid was dissolved
in water to give 56.5 mL of solution. This
solution was titrated with 0.260 M NaOH .
What was the pH of the solution when the equivalence point was
reached? Ka of benzoic acid is 6.3x10 to the negative fifth .
A 0.520 g sample of a diprotic acid with a molar mass of 255.8
g/mol is dissolved in water to a total volume of 23.0 mL . The
solution is then titrated with a saturated calcium hydroxide
solution.
a. Assuming that the pKa values for each ionization step are
sufficiently different to see two equivalence points, determine the
volume of added base for the first and second equivalence
points.
b. The pH after adding 23.0 mL of the base was...
You have a 1.153 g sample of an unknown solid acid, HA,
dissolved in enough water to make 20.00 mL of solution. HA reacts
with KOH(aq) according to the following balanced chemical
equation: HA(aq)+KOH(aq)--->KA(aq)+H2O(l)
if 13.40 mL of 0.715 M KOH is required to titrate the unknown
acid to the equivalence point, what is the concentration of the
unknown acid? ALSO What is the molar mass of HA?
A 0.1219 g sample of a Vitamin C (ascorbic acid) tablet was
dissolved in acid. A 25.00 mL aliquot of 0.01739 M KIO3 was added
along with excess KI. The resulting solution was titrated with
0.07211 M thiosulfate, requiring 21.44 mL to reach the endpoint.
Compute the weight percent of ascorbic acid (FW = 176.12) in the
tablet.