Question

Hi! i need to calculate the Ka for acetic acid from an experiment using an ice...

Hi! i need to calculate the Ka for acetic acid from an experiment using an ice diagram but my Ka value keeps coming up negative. I'm using the pH of the acetic acid before titration with NaOH (pH = 2.96) to get [H3o+] and [OAc] to equal 10^(-2.96) which is 1.1x10-3. And the moles of acid in my original flask was 0.004 HOAc, so can someone show me the calculations if I am doing them wrong or help me figure out what I may be doing wrong? Thank you!

Homework Answers

Answer #1

First, write the Ka expression

HA = H+ + A-

where HA is acetic acid, A- acetate, and H+ the acidic proton

then

Ka = [H+][A-]/[HA]

we need, in equilbirium

[H+]= x

[A-] = x

[HA] = M-x

we already have M = 0.004 M

[H+]= x

[A-] = x

[HA] = 0.004 -x

and we can get x via pH

[H+] = x= 10^-ph = 10^-2.96 = 0.0010964

now,... x = 0.0010964

[H+]= x = 0.0010964

[A-] = x = 0.0010964

[HA] = 0.004 -x = 0.004-0.0010964 = 0.0029036

substitute in Ka

Ka = [H+][A-]/[HA]

Ka = (0.0010964)(0.0010964)/0.0029036

Ka = 0.00041400

Ka = 4.14*10^-4

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
I need to find the pKa and Ka value of CH3COOH for my Acid-Base titration experiment....
I need to find the pKa and Ka value of CH3COOH for my Acid-Base titration experiment. It’s pH before titration is 2.37 pH at equivalence point is 9.17 [H3O+] before titration is .00427 [H3O+] at equivalence point is 0.99 (Don’t know if it’s needed but the midpoint on the titration curve is (5.5ml, 7.49ph) . . Step by step explanation would be helpful!
Hi there, I am asked to calculate for the millimoles of acetic acid in a sample...
Hi there, I am asked to calculate for the millimoles of acetic acid in a sample for a lab (Determination of the molar mass and ionization constant of a weak acid) this lab was performed with titration of 0.10 M NaOH into a 30.615g of acetic acid. Measured pH of the acetic acid sol’n Trial 1 Mass of acetic acid sol’n taken for the tritation 30.615g Initial buret reading of NaOH tritrant 0.00ml Final buret reading of NaOH tritrant 12.6ml...
6d. A buffer solution is made using acetic acid and its conjugate base with equal concentrations...
6d. A buffer solution is made using acetic acid and its conjugate base with equal concentrations of 3.00 moles/liter. If the Ka of acetic acid is 1.8x10^-5 calculate the change o\in pH on addition of 0.15 M nitric acid (HN03). 6e. Sketch a graph for a titration of a weak acid (burette) against 25 cm^3 of strong base (conical flask). Assume that both have a concentration of 0.5M. Label axes.
5. (6 pts) The pH of an acetic acid (CH3COOH) solution is 6.20. Calculate the concentration...
5. (6 pts) The pH of an acetic acid (CH3COOH) solution is 6.20. Calculate the concentration of hydronium ion (H3O+, in M) in this solution. (Ka = 1.8 x 10–5) 3 For questions 6-8, consider the titration of of 5.00 mL of 0.450 M HBr using 0.120 M NaOH as the Btrant. 6. (6 pts) Calculate the volume of 0.120 M NaOH that must be added in order to reach the equivalence point.
Calculate the [H3O+] and the concentrations of A- and HA in the 1/2 neutralized solution. (Note...
Calculate the [H3O+] and the concentrations of A- and HA in the 1/2 neutralized solution. (Note that [H3O+} does not equal [A-]). The mass of acetic acid solution is 30.01 g Volume of the NaOH added to 1/2 neutralize the acetic acid is 6.2 mL Measured pH of 1/2 neutralized solution is 4.8 The concentration of standardization NaOH titration is 0.09755 mol/L The average pH value is 4.8 PKa 4.8 Ka 1.58x10^-5 ** In my notes it says that the...
1. Calculate the pH of a solution that is 0.050 M acetic acid and 0.010 M...
1. Calculate the pH of a solution that is 0.050 M acetic acid and 0.010 M phenylacetic acid. Express your answer using two decimal places. 2. Calculate the pH at the points in the titration of 25.00 mL of 0.136M HNO2 when the following amounts of 0.122M NaOH have been added. For HNO2, Ka=7.2
Calculate the pH during the titration of 40.00 mL of a 0.1000 M propanoic acid (Ka...
Calculate the pH during the titration of 40.00 mL of a 0.1000 M propanoic acid (Ka = 1.3 x 10^-5) after each of the following volumes of 0.1000M NaOh has been added. Use ICE tables to show your work. a) 0.00 mL b) 25.00 mL c) 40.00 mL d) 50.00 mL The answers are: a. 2.96 b. 5.12 c. 8.80 d. 12.05 Show work on how you arrive to each solution.
I need to find the M of citric acid from my lab experiment. (This is a...
I need to find the M of citric acid from my lab experiment. (This is a common titration experiment with NaOH solution and citric acid soda. H3C6H5O7 (aq) +3NaOH (aq) ---> Na3C6H5O7 (aq) + 3H2O (l) The average molarity of my NaOH solution is 0.00896. My first trial resulted in a net 13.26mL. Molar mass of citric acid is 192.12352. How do I figure Mcitirc acid? Mol/can (355 mL) and g citric acid/can?
Hi there, I did an experiment using the titration of EDTA to determine the hardness of...
Hi there, I did an experiment using the titration of EDTA to determine the hardness of water. 1.)How do I determine the amount of moles of EDTA? 2.)How do I find the average water hardness of the water I used in this experiment? I started with 10 ml of water, added 5 drops of Ph 10 to it, and then EBT indicator. I then used the tirator to dispense EDTA into the beaker to find out if how much EDTA...
1.) You will work with 0.10 M acetic acid and 17 M acetic acid in this...
1.) You will work with 0.10 M acetic acid and 17 M acetic acid in this experiment. What is the relationship between concentration and ionization? Explain the reason for this relationship 2.) Explain hydrolysis, i.e, what types of molecules undergo hydrolysis (be specific) and show equations for reactions of acid, base, and salt hydrolysis not used as examples in the introduction to this experiment 3.) In Part C: Hydrolysis of Salts, you will calibrate the pH probe prior to testing...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT
Active Questions
  • A gigantic warehouse stores approximately 40 million empty aluminum beer and soda cans.​ Recently, a fire...
    asked 2 minutes ago
  • 5. There are many complaints from passengers about the late running of buses on a particular...
    asked 6 minutes ago
  • (1 point) A survey of 1780 people who took trips revealed that 117 of them included...
    asked 10 minutes ago
  • Implement the following circuit to test the characteristics of a D flip flop. Note: Using a...
    asked 14 minutes ago
  • Next, suppose you add the unemployment rate, as a variable, to the regression model above and...
    asked 15 minutes ago
  • In a recent random sample, where 600 adults were surveyed, 16.4% indicate that they have fallen...
    asked 18 minutes ago
  • Suppose that you estimate the following regression: SALES = 5.467-1.034(PRICE) A) How do you interpret the...
    asked 23 minutes ago
  • Consider the following scenario: An industrial seller of grass seeds packages its product in 50-pound bags....
    asked 26 minutes ago
  • ​(Bond valuationlong dash—zero coupon​) The Latham Corporation is planning on issuing bonds that pay no interest...
    asked 42 minutes ago
  • The article “Doctors Cite Burnout in Mistakes” reported that doctors completing residency have financial struggles that...
    asked 44 minutes ago
  • The frame for an education survey includes 2000 high schools, each of which contain 1000 students....
    asked 46 minutes ago
  • Professor Gersch grades his midterms and then takes a sample of eight tests and notices their...
    asked 56 minutes ago