# Chemistry

Find the pH during the titration of 20.00 mL of 0.2380 M butanoic acid, CH3CH2CH2COOH (Ka = 1.54 10-5), with 0.2380 M NaOH solution after the following additions of titrant.
(a) 0 mL
Ive got the answer of 2.72
(b) 10.00 mL
Ive got the answer of 4.81
(c) 15.00 mL

(d) 19.00 mL

(e) 19.95 mL

(f) 20.00 mL

(g) 20.05 mL

(h) 25.00 mL

c,d,e are all done essentially the same way. I will go through c.
For simplicity in typing, I will call butanoic acid a simple HB. Then
butanoic acid + KOH = potassium salt of butanoic acid + H2O OR in simple terms:
HB + KOH ==> KB + H2O
mols HB at beginning of titration are L x M = 0.020 x 0.2380 = ??
mols KOH added = (for c) 0.015 x 0.2380 = ??
Subtract from HB to see how much HB is left. Add to KB to see how much B^- is there. Plug into the Henderson-Hasselbalch equation and solve for pH.
d and e are done essentially the same way.
For f you must recognize that 20.00 mL KOH is the EXACT equivalence point; therefore, the pH is determine SOLELY by the amount of salt (KB) present and that is determined by the hydrolysis of the salt. Using the Bronsted-Lowry theory of acids/bases, write the hydrolysis of the anion, B^-.
B^- + HOH ==> HB + OH^-
Post back if you don't know what to do with that.

For the others AFTER the equivalence point, these are just excess KOH so you need to calculate how much excess KOH is present, the total volume of the solution, and the molarity of the KOH present at those points. Then use pH + pOH = pKw
I shall be happy to check your work if you post it.

1. 👍 0
2. 👎 0
3. 👁 254
1. A solution of ammonia and water contains 3.10×1025 water molecules and 5.20×1024 ammonia molecules. How many total hydrogen atoms are in this solution?

1. 👍 0
2. 👎 0
posted by tb

## Similar Questions

1. ### chemistry

Find the pH during the titration of a 20.00mL of 0.1000 M butanoic acid, CH3CH2CH2COOH (Ka=1.54 x10^-5), with the addition of 10 mL of 0.1000 M NaOH solution??

asked by anonymous on April 9, 2012
2. ### Chemistry

Find the pH during the titration of 20.00 mL of 0.1000 M butanoic acid, CH3CH2CH2COOH (Ka = 1.54e-5), with 0.1000 M NaOH solution after the following additions of titrant: 0 mL, 14.00 mL, 19.95 mL, 20.00 mL, 20.05 mL, 24.00 mL.

asked by James on November 23, 2011
3. ### chemistry

Calculate the pH during the titration of 20.00 mL of 0.1000 M CH3CH2CH2COOH with 0.1000 M NaOH after 26.5 mL of the base have been added. Ka of butanoic acid = 1.54 x 10-5.

asked by karla on October 31, 2010
4. ### chemistry

Calculate the pH during the titration of 20.00 mL of 0.1000 M CH3CH2CH2COOH with 0.1000 M NaOH after 26.5 mL of the base have been added. Ka of butanoic acid = 1.54 x 10-5.

asked by karla on October 31, 2010
5. ### Organic Chemistry

what is the name of the amide that is formed by the following reaction: Butanoic acid + Methylamine? - CH3CH2CH2COOH + CH3NH2 ---> product + H2O? i put n-methylbutyramide and they counted it wrong.

asked by Tina on January 21, 2010
6. ### chemistry

The question asks, "Butanoic acid has a partition coeff of 3.0 when distributed b/t water and benzene. Find the formal concentration of butanoic acid in each phase when 100 mL of 0.10 M aqueous butanoic acid is extracted with 25

asked by Anonymous on November 15, 2009
7. ### Chemistry (Acid-Base)

Butanoic acid (Ka = 1.52 x 10-5) has a partition coefficient of 3.0 (favouring benzene) when distributed between water and benzene. Find the concentration of butanoic acid in each phase when 20.0 mL of 0.10 M aqueous butanoic acid

asked by Daniel on January 21, 2015
8. ### Chemistry

Butanoic acid (Ka = 1.52 x 10-5) has a partition coefficient of 3.0 (favouring benzene) when distributed between water and benzene. Find the concentration of butanoic acid in each phase when 20.0 mL of 0.10 M aqueous butanoic acid

asked by Daniel on January 19, 2015
9. ### chemistry

Butanoic acid consists entirely of C, H and O. Upon combustion, a 0.3164g sample of butanoic acid produces 0.6322g CO2 and 0.2588g H2O. Determine the empirical formula of butanoic acid I don't want the answer just direction on how

asked by balanciaga on June 11, 2016
10. ### Chemistry

Use activity coefficients to find the concentration of hydrogen ions in a solution of 65.0 mM butanoic acid and 0.01 M NaCl. The ionization constant of butanoic acid is Ka = 1.52 × 10-5. Take the size of C3H7COO– to be 500 pm.

asked by Jessica on March 12, 2013

More Similar Questions