The value of Ka in water at 25 °C for propionic acid (C2H5CO2H) is 3.4 x...

The value of Ka in water at 25 °C for propionic acid (C2H5CO2H) is 3.4 x 10-5 M. What is the pH of a 0.020 M aqueous solution of propionic acid?

Expert Solution

proponoic acid is a week acid

construct the ICE table

C2H5CO2H + H2O <------> C2H5CO2^- + H3O+

I 0.02 0 0

C -x +x +x

E 0.02-x +x +x

now dissociation constant

Ka = [C2H5CO2-][H3O+] / [C2H5CO2H]

3.4 x 10^-5 = [x][x] / [0.02-x]

x² + x 3.4 * 10-5 - 6.8 x 10^-7 = 0

solve the quadratic equation to get x value

x = 0.0008078 M = [H3O+]

now

pH = -log[H3O+] = -log[0.0008078] = 3.09

queen_honey_blossom answered 2 years ago

If the Ka of a monoprotic weak acid is 3.4 × 10-6, what is the pH...

If the Ka of a monoprotic weak acid is 3.4 × 10-6, what is the pH of a 0.34 M solution of this acid?

25.00 cm3 of 1.000 M propionic acid (structure CH3CH2COOH ) ( Ka = 1.34×10−5 ) is...

25.00 cm3 of 1.000 M propionic acid (structure CH3CH2COOH ) ( Ka = 1.34×10−5 ) is titrated with 0.910 M NaOH. What is the pH of the solution a) before any NaOH is added? b) at half-neutralization? c) at the equivalence point? d) when 0.10 mL less than the volume of NaOH to reach the equivalence point is reached? e) when 0.10 mL more than the volume of NaOH to reache the equivalence point is reached? f) Use your data...

1. The Ka of hypochlorous acid (HCLO) is 3.0x10-8. What is the pH at 25 C...

1. The Ka of hypochlorous acid (HCLO) is 3.0x10-8. What is the pH at 25 C of an aqueous solution that is .0200 M in HCLO? 2. A .10 M aqueous solution of the weak base B at 25 C has a pH of 8.00. The Value of Kb for B is _____.

For nitrous acid, HNO2, the value of Ka is 4.0 x 10-4. a. What is the...

For nitrous acid, HNO2, the value of Ka is 4.0 x 10-4. a. What is the formula of the conjugate base of HNO2? b. What is the pH of a 0.250 M solution of this weak acid HNO2?

Determine the pH of each solution. Dissociation Constants at 25 ∘C Name Formula Ka Formic acid...

Determine the pH of each solution. Dissociation Constants at 25 ∘C Name Formula Ka Formic acid HCHO2 1.8×10−4 Name Formula Kb Methylamine CH3NH2 4.4×10−4 a) 0.21 M KCHO2 b) 0.21 M CH3NH3I c)0.21 M KI

The Henry's Law constant for CO2 is 3.4 x 10-2 M/atm at 25°C. What pressure of...

The Henry's Law constant for CO2 is 3.4 x 10-2 M/atm at 25°C. What pressure of carbon dioxide is needed to maintain a CO2 concentration of 0.10 M in a can of soda?

Acetic acid is a monoprotic weak acid with a pKa of 4.74. (Ka = 1.8 x...

Acetic acid is a monoprotic weak acid with a pKa of 4.74. (Ka = 1.8 x 10-5) (a) What is the pH of 5 mL of a 5.0% solution? (b) What is the pH of the solution if you now add 45 ml of water to solution (a)? How will the equivalence point volumes differ if you titrate the two solutions ?

part A. Formic acid, HFor, has a Ka value equal to about 1.8 x 10-4. A...

part A. Formic acid, HFor, has a Ka value equal to about 1.8 x 10-4. A student is asked to prepare a buffer having a pH of 3.55 from a solution of formic acid and a solution of sodium formate having the same molarity. How many milliliters of the NaFor solution should she add to 20 mL of the HFor solution to make the buffer? part B. how many ml of 0.10 m naoh should the student add to 20...

1) Explain what a high Ka value of an acid represents and what a low Ka...

1) Explain what a high Ka value of an acid represents and what a low Ka value represents. 2) State and explain the difference between the endpoint and the equivalence point in a titration.

You have a one liter solution of kerosene containing 25 wt% propionic acid, add one liter...

You have a one liter solution of kerosene containing 25 wt% propionic acid, add one liter of water, mix thoroughly and allow the two phases to settle. At this temperature, the distribution coefficient for propionic acid is 0.175 mass fraction in kerosene/mass fraction in water. What is the expected composition (wt%) and mass (kg) of the two phases? You may need to acquire physical properties for some of your species.

Question