Question

In: Chemistry

Show how you would find the concentration of a diprotic acid that was titrated with NaOH?...

Show how you would find the concentration of a diprotic acid that was titrated with NaOH? Find the concentration of a diprotic acid when 24.55mL of the acid requires 32.57 mL of 0.1059 M NaOH.

Solutions

Expert Solution

H2A(aq) + 2 NaOH(aq) ---> Na2A(aq) + 2 H2O(aq)

So, once you assured to used only 0.1059 M CONCENTRATED SOLUTION OF STRONG BASE (e.g. NaOH) WHICH OCCURRED IN MEASURE LIKE 32.57 mL AGAINST 24.55 mL OF UNKNOWN ACID.
ONCE I WROTE "NET IONIC REACTION"

2 H+(aq) + 2 OH-(aq) ---> 2 H2O(aq)

I HIGHLIGHTED THAT NaOH IS MONOVALENT BASE SINCE IT GIVES ONE HYDROXYL ION (e.g. OH- which comes from Arrhenius definition of BASEs). ON THE OTHER HAND, H2A IS BIVALENT ACID SINCE IT GIVES TWO HYDROGEN ION (e.g. H+ which comes from Arrhenius definition of ACIDs).
So, YOU PLAYED BY A MONOVALENT BASE AND A BIVALENT ACID.


CONCLUSION
The mathematical relationship is

(n,acid * M,acid) * V,acid = (n,base * M,base) * V,base

where

n,acid = 2
n,base = 1
V,acid = 24.55 mL
V,base = 32.57 mL
M,base = 0.1059 M

so it has to be

M,acid = (n,base * M,base) * V,base / (n,acid * V,acid) =
= (1 * 0.1059) * 32.57 / (2 * 24.55) = 0.070 M


Related Solutions

Weak diprotic acid H2A is titrated with 0.2000 M NaOH. The initial concentration of H2A is...
Weak diprotic acid H2A is titrated with 0.2000 M NaOH. The initial concentration of H2A is 0.1000 M and the initial volume is 50.00 mL.      Ka1 = 1.0 x 10−5       Ka2 = 1.0 x 10−9 (a) (0.2 pt) Identify the predominate species at the first equivalence point, by chemical formula: (b) (0.5 pts) Calculate the pH of the acid solution before any base is added. (c) (0.5 pts) Calculate the pH at the first equivalence point. (d) (0.2 pts)...
96.0 mL of a NaOH solution of unknown concentration is titrated with 4.00 M hydrochloric acid,...
96.0 mL of a NaOH solution of unknown concentration is titrated with 4.00 M hydrochloric acid, HCl. The end point is reached when 150.0 mL of acid are added to the base. What is the concentration of the original NaOH solution? a. 1.56 mol/L b. 3.13 mol/L c. 6.26 mol/L d. 12.5 mol/L
50.0 ml of an acetic acid (CH3COOH) of unknown concentration is titrated with 0.100 M NaOH....
50.0 ml of an acetic acid (CH3COOH) of unknown concentration is titrated with 0.100 M NaOH. After 10.0 mL of the base solution has been added, the pH in the titration flask is 5.30. What was the concentration of the original acetic acid solution? (Ka(CH3COOH) = 1.8 x 10-5)
20.0mL of 0.127M diprotic acid (H2A) was titrated with 0.1018M KOH. The acid ionization constants for...
20.0mL of 0.127M diprotic acid (H2A) was titrated with 0.1018M KOH. The acid ionization constants for the acid are Ka1=5.2
Phathalic acid, H2C8H4O4, is a diprotic acid and has a concentration of 2.9 M. Ka1 =...
Phathalic acid, H2C8H4O4, is a diprotic acid and has a concentration of 2.9 M. Ka1 = 0.0012 and Ka2 = 3.9 x 10-6. Estimate the concentration of [HC8H4O4-] and [C8H4O4-2] at equilibrium. Determine Kb1 and Kb2. Determine the pH of the solution at each proton dissociation. 11. Calculate the molar solubility of calcium hydroxide (Ksp = 4.8 x 10^6 I NEED TO KNOW HOW DID THEY GET THIS ANSWER PLEASE 0.0012 = x2/2.9 x = 0.059 M equilibrium concentration of...
sketch the general appearance of the curve for the titration of weak diprotic acid with NaOH....
sketch the general appearance of the curve for the titration of weak diprotic acid with NaOH. what chemistry governs the pH in each distinct region of the curve
A 40.00 mL sample of 0.1000 M diprotic malonic acid is titrated with 0.0900 M KOH....
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...
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
0.901g KHP is fully titrated with 44.1 mL of an NaOH solution of unknown concentration. What...
0.901g KHP is fully titrated with 44.1 mL of an NaOH solution of unknown concentration. What is the concentration of the NaOH solution? (Report to 3 sig figs).
Four solutions of unknown HCl concentration are titrated with solutions of NaOH. The following table lists...
Four solutions of unknown HCl concentration are titrated with solutions of NaOH. The following table lists the volume of each unknown HClsolution, the volume of NaOH solution required to reach the equivalence point, and the concentration of each NaOH solution. HCl Volume (mL) NaOH Volume (mL) [NaOH](M) 22.00 mL 31.44 mL 0.1231 M 12.00 mL 21.22 mL 0.0972 M 25.00 mL 10.88 mL 0.1088 M 3.00 mL 7.88 mL 0.1225 M Part A Calculate the concentration (in M) of the...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT