A 125.0 mg sample of an unknown, monoprotic acid was dissolved in 100.0 mL of distilled water and
titrated with a 0.050 M solution of NaOH. The pH of the solution was monitored throughout the titration,
and the following data were collected. Determine the Ka of the acid.
Volume of
OH- (mL) 0 5 10 15 17 18 19 20 21 22 22.2 22.6 22.8 23 24 25 30 40
pH 3.09 3.65 4.10 4.50 4.55 4.71 4.94 5.11 5.37 5.93 6.24 9.91 10.2 10.4 10.8 11.0 11.5 11.8

  1. 👍 0
  2. 👎 0
  3. 👁 865
  1. Plot the data as pH on the y axis and mL on the x axis. Locate the equivalence point, read the mL, divide that by 2 and read the pH at that mL mark (the mL/2 mark that is) and that will be the pKa value for the weak acid.

    1. 👍 0
    2. 👎 1

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    A 0.040M solution of a monoprotic acid is 14% ionized. Calculate the Ka for the weak acid. ---------------- so: HX H+ + X- Ka= [H+][X-]/ [HX] Since its a monoprotic acis i know the concentration of H and X will be equal And the HX

  2. Chemistry (College) URGENT

    1.6g of an unknown monoprotic acid (HA) required 5.79 mL of a 0.35 M NaOH solution to reach the equivalence point. Determine the molar mass of the acid and given that the pH at the half way point to the equivalent point is 3.86.

  3. Chem

    A sample contains an unknown amount of tartaric acid, H2C4H4O6. If 0.3888 g of the sample requires 37.74 mL of 0.1000 M NaOH to neutralize the H2C4H4O6 completely, what is the percentage of H2C4H4O6 in the sample? The molar mass

  4. Chemistry

    The pH of a 0.095 M solution of an unknown monoprotic acid is 5.42. Calculate the Ka of the acid. A) 3.8 x 10-6 B) 3.6 x 10-7 C) 1.5 x 10-10 D) 2.6 x 10-9 E) 2.8 x 10-8 ​

  1. Chemistry

    Determine the molar mass of the unknown acid.? A 0.167-g sample of an unknown acid requires 27.8 mL of 0.100 M NaOH to titrate to the equivalence point. Elemental analysis of the acid gives the following percentages by mass:

  2. Chemistry

    If 14.23 mL of 0.203 M NaOH is required to neutralize .269 g of a monoprotic unknown acid, what is the molecular weight of the unknown acid?

  3. Chemistry

    A .288 g sample of an unknown monoprotic organic acid is dissolved in water and titrated with a .115 M sodium hydroxide solution. After the addition of 17.54 mL of base, a pH of 4.92 is recorded. The equivalence point is reached

  4. Chemistry

    We will calculate the amount of acid to use in each titration. Assume that you are using 0.0512 M NaOH(aq). A good volume of NaOH(aq) to use per titration is 15 mL. From this molarity and volume, the moles of NaOH can be

  1. Chemistry

    An unknown solid acid is either citric acid or tartaric acid. To determine which acid you have, you titrate a sample of the solid with NaOH. The appropriate reactions are as follows: Citric acid: H3C6H5O7 (aq) + 3NaOH (aq) -> 3H2O

  2. Chemistry

    Explain why acetic acid has four hydrogens, but is a monoprotic acid The formula for acetic acid is CH3COOH so yes it does have four hydrogens. But the only hydrogen that is able to easily come off and be donated to another

  3. chem-please help!!!!!

    when a 25.0 mL sample of an unknown acid was titrated with a 0.100 M NaOH solution. Determine Ka for the unknown acid. Volume NaOH = 25 mL; pH=8.25

  4. Chemistry

    Item 1 Maleic acid is a carbon-hydrogen-oxygen compound used in dyeing and finishing fabrics and as a preservative of oils and fats. •In a combustion analysis, a 1.054-g sample of maleic acid yields 1.599 g of CO2 and 0.327 g of

You can view more similar questions or ask a new question.