The results we get from a weak acid-strong base titration is given .
Here , we assume , the weak acid to be acetic acid equivalent , having concentration to be 0.1 N . 50 ml of this is taken .
ka of acetic acid is is 1.8*10-5 . We put the value here .
Take NaOH equivalent to be the strong base , with a concentration 0.1 N .
Initial
Here , no base present . The formula to put is ,
Middle
Here , we use Henderson-Hasselbalch equation of buffer . The equation is ,
Now , by addition of base , [salt] &[acid] changes and pH alters . A pH table is given by addition of base.
NaOH added(ml) | pH |
1 | 3.05 |
5 | 3.78 |
10 | 4.13 |
15 | 4.37 |
20 | 4.56 |
25 | 4.74 |
30 | 4.92 |
35 | 5.10 |
40 | 5.34 |
45 | 5.69 |
49 | 6.43 |
49.5 | 6.74 |
Equivalence
At equivalence point , Salt Hydrolysis occurs . The equation is -
After Equivalence
Here ,
NaOH = 50.5 ml , pH=10.69
NaOH = 51 ml , pH=10.99
NaOH = 52 ml , pH=11.29
Now , we are going to plot it .
To determine the pKa , we use the pH corresponding to the half neutralisation point (here , 25 mL)
At 25 ml , pH=4.74 we get . That is the pKa .
For weak base-strong acid titration , pOH vs. Acid equivalance plot looks alike the plot shown . We can get pH=14-pOH
Thus , the plot of pH vs. Acid equivalance will be invert of that in y axis top .
The plot will look like ,
You can do the calculations in same way , just replacing pH by pOH .
with at least 10 data points choose a weak acid (such as formic acid, acetic acid,...
Prepare a titration curve (pH vs. equivalents strong base added if you choose a weak acid to be titrated) in which you plot at least 10 data points starting from 0-equiv added to 1 equiv added. Show how you can obtain the pKa for this acid from the plot. You can also choose a weak base to be titrated with strong acid. Use Excel for the calculations and for plotting. Show the calculations for how you obtained the pH at...
24A) 40mL of 0.2 M formic acid is titrated with a strong base (NaOH= 0.5 M). Determine the pH before any base has been added. Please show steps and please explain why the answer is what it is. 24B) The 40mL 0.2 M formic acid is titrated with a 6.0mL of strong base. Here NaOH can be treated as a conjugate base and formic acid is the acid. please show steps and explain! Us (24-25, Acid/base, aqueous equilibrium) 24A) (4...
When a 0.1M solution of a weak acid was titrated with base, the following results were obtained: Equivalents of base added pH observed 0.05 3.4 0.15 3.9 0.25 4.2 0.40 4.5 0.60 4.9 0.75 5.2 0.85 5.4 0.95 6.0 Plot the results of this titration and determine the pKa of the weak acid from your graph.
20) the pH at the half titrated point of a weak acid strong base titration curve is 4.15, what is the pka and the for the weak acid being titrated 9 7.08X10-9 Opha 4.15
Carry out a serial titration of one drop of the weak base 0.05 M NH, (aka NH,OH) with 0.01 M HCI. Stir. Measure the pH values of the solutions. Plot the titration curve on the same graph with your strong acid/strong base and weak acid/strong base titration curves. Compare with the computer-simulated curve (Figure 14.7). NOTE: Data from the computer calculation give an equivalence point pH of 5.70 at 5.0 drops of added 0.01 M HCI. Observations: Lane 1-purple (pH...
13. Sketch a titration curve for the titration of a monoprotic weak acid HA with a strong base. The titration reaction (neutralization) is: HA + OH + H2O+ A On the curve, clearly label the points that correspond to: i. the equivalence point ii. the region with maximum buffering iii. pH = pka iv. pH depends only on [HA] v. pH depends only on [A-] vi. pH depends only on amount of strong base added.
Question: In the figure below, titration curves for strong acid with strong base and weak acid with strong base are shown. Compare the shapes of these curves early in the titration for three different cases: titration of a strong acid, titration of a weak acid with a lower pKa, and titration of a weak acid with a higher pKa. Discuss with the class why the titration curve for weak acids increase more rapidly early in the titration than do stronger...
3) (10 points total) A 25.0-mL sample of 0.35 M HCOOH (formic acid) is titrated with 0.20 M KOH. What is the pH of the solution after 25.0 mL of KOH has been added to the acid? Ka-1.77 x 10 a) (4 points) What is the pH of the solution after 25.0 mL of KOH has been added to the acid? Ks-1.77 x 10 C 2-l04Co1s5 b) (6 points) Calculate at least nine (9) more titration points, build a table...
2) (10 points total) (Problem 16.145 from your text (Tro)) Lactic acid is a weak a calcium salt is a source of calcium for growing animals. A saturated solution of this salt, which we can your text (Tro)) Lactic acid is a weak acid found in plks represent as Ca(Lact), has a [Ca²+] -0.26 M and a pH - 8.78. Assuming the salt is completely dissociated, calculate the K, of the acid. (Show all work for full credit) PH=2A] =...
Consider the curve shown here for the titration of a weak base with a strong acid and answer each question. a. What is the pH and what is the volume of added acid at the equivalence point? b. At what volume of added acid is the pH calculated by working an equilibrium problem based on the initial concentration and Ks of the weak base? c. At what volume of added acid does pH = 14 - pka ? d. At what volume of added...