Question

In: Chemistry

Methanoic acid has a Ka=1.6X10-4. Calculate the pH of the final solution when 23.90 mL of...

Methanoic acid has a Ka=1.6X10-4. Calculate the pH of the final solution when 23.90 mL of 0.100M NaOH is added to 25.00 mL of 0.100 M methanoic acid

Solutions

Expert Solution

Ka = 1.6 x10^-4

NaOH = 23.90 ml of 0.100M

number of moles of NaOH = 0.100M x 0.02390L = 0.00239 moles

Methanoic acid = 25.00ml of 0.100M

number of moles of Methanoic acid = 0.100M x 0.02500L = 0.0025 moles

Ka = 1.6 x 10^-4

-log(Ka) = -log(1.6 x10^-4)

Pka = 3.79

Methanoic acid = HCOOH

                   HCOOH     +    NaOH ---------------------   HCOONa      + H2O

Initial            0.0025           0.00239                                   0

change    - 0.00239        - 0.00239                              + 0.00239

equilibrium               0.00011                0                                   + 0.00239

PH = Pka + log[salt]/[acid]

PH = 3.79 + log(0.00239/0.00011)

PH = 5.13

PH of the solution = 5.13


Related Solutions

Nitrous acid has a Ka of 4.0x10-4. Calculate the pH when 40.00 mL of 0.125 M...
Nitrous acid has a Ka of 4.0x10-4. Calculate the pH when 40.00 mL of 0.125 M HNO2 is titrated against 0.200 M NaOH and reaches the equivalence point.
Calculate the pH of a 0.500M formic acid (HCOOH) solution. Ka for formic acid is 1.8×10-4.
Calculate the pH of a 0.500M formic acid (HCOOH) solution. Ka for formic acid is 1.8×10-4.
Calculate the final pH of a solution made by the addition of 10 mL of a...
Calculate the final pH of a solution made by the addition of 10 mL of a 0.5 M NaOH solution to 500 mL of a weak acid, HA. The concentration of the conjugate acid is 0.2M, the pH is 5.00 and thepKa = 5.00. Neglect the change in volume. (This is all of the information that was given.) a.6.10 b. 5.04 c. 7.00 d. 5.99 e. 6.91
Calculate the pH and pOH of a 0.50 M solution of Acetic Acid. The Ka of...
Calculate the pH and pOH of a 0.50 M solution of Acetic Acid. The Ka of HOAc is 1.8 x10-5 [H3O+]/(0.50-0.00095)=1.8x10-5 where did they get the .00095, its said to take that as the second assumption [H3O+]=9.4x10-4 [H3O+]/(0.50-0.00094)=1.85x10-5 [H3O+]=9.4x10-4 (this is said to be the third assumption) Please, please help I really dont understand this, please show all steps and be as descriptive as possible.
Calculate the pH when 15.0 mL of 0.20 M Benzoic Acid (HC7H5O2 Ka = 6.5x10-5) is...
Calculate the pH when 15.0 mL of 0.20 M Benzoic Acid (HC7H5O2 Ka = 6.5x10-5) is titrated with 20.0 mL of 0.15 M sodium hydroxide (NaOH) Can you exaplain how to solve this question?
Calculate the values of pH when 40.0 mL of 0.0250M benzoic acid (HC7H5O2 , Ka=6.3x10-5 )...
Calculate the values of pH when 40.0 mL of 0.0250M benzoic acid (HC7H5O2 , Ka=6.3x10-5 ) is titrated with (1) 0.0 mL of 0.050 M NaOH solution? (2) 10.0 mL of 0.050 M NaOH solution? (3) 25.0 mL of 0.050 M NaOH solution? I mostly need help with 2 and 3. The answers are 4.20 and 11.58 but I not know how to calculate them.
Calculate the pH of the solution that results when 15.0 mL of 0.1650 M lactic acid...
Calculate the pH of the solution that results when 15.0 mL of 0.1650 M lactic acid is A) diluted to 45.0 mL with distilled water B)mixed with 30.0 mL of 0.0825 M NaOH solution. C)mixed with 30.0 mL of 0.140 M NaOH solution. D)mixed with 30.0 mL of 0.140 M sodium lactate solution.
Calculate the pH of a 0.0152 M aqueous solution of nitrous acid (HNO2, Ka = 4.6×10-4)...
Calculate the pH of a 0.0152 M aqueous solution of nitrous acid (HNO2, Ka = 4.6×10-4) and the equilibrium concentrations of the weak acid and its conjugate base. pH = [HNO2]equilibrium = M [NO2- ]equilibrium = M
The weak acid HZ has a Ka of 2.55 x 10-4. Calculate the pH of a...
The weak acid HZ has a Ka of 2.55 x 10-4. Calculate the pH of a 0.235 M solution.
Calculate the pH of a titration of 50.00 mL of 0.100 M Phenylacetic acid , Ka...
Calculate the pH of a titration of 50.00 mL of 0.100 M Phenylacetic acid , Ka = 4.9 x 10-5, with 0.100 M NaOH at the following points: SHOW ALL WORK IN NEAT DETAIL ON A SEPARATE PAGE. (Be sure to write chemical equations and Ka or Kb expressions when needed.) a. (4 Pts) Before any NaOH is added. b. (4 Pts) After 18.7 mL of NaOH are added. c. (4 Pts) After 25.00 mL of NaOH are added. d....
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT