Drill determine the ph of 0 25 m hz k ahz 2 5 x 10 7
Download
1 / 24

Drill: Determine the pH of 0.25 M HZ. K aHZ = 2.5 x 10 -7 - PowerPoint PPT Presentation


  • 103 Views
  • Uploaded on

Drill: Determine the pH of 0.25 M HZ. K aHZ = 2.5 x 10 -7. Buffer Solutions. Buffer Solution. A solution that resists changes in pH. Buffer Solution. Made from the combination of a weak acid & its salt. Buffer Solution. Made from the combination of a weak base & its salt. Buffer Examples.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Drill: Determine the pH of 0.25 M HZ. K aHZ = 2.5 x 10 -7' - tudor


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript


Buffer solution
Buffer Solution

  • A solution that resists changes in pH


Buffer Solution

  • Made from the combination of a weak acid & its salt


Buffer Solution

  • Made from the combination of a weak base & its salt


Buffer Examples

  • Mix acetic acid & sodium acetate

  • Mix ammonia & ammonium chloride


Buffer Solution

  • A buffer solution works best when the acid to salt ratio is

  • 1 : 1


Buffer Solution

  • A buffer solution works best when the base to salt ratio is

  • 1 : 1


Buffer Solution

  • The buffering capacity of a solution works best when the pH is near the pKa


pKa or pKb

  • pKa = - log Ka

  • pKb = - log Kb


Buffer Problems

  • Calculate the pH of a solution containing 0.10 M HAc in 0.10 M NaAc: Ka = 1.8 x 10-5


Buffer Problems

  • Calculate the pH of 0.10 M NH3 in 0.20 M NH4NO3:

  • Kb = 1.8 x 10-5


Buffer Problems

Calculate the pH of a solution containing

0.10 M HBz in 0.20 M NaBz: Ka = 6.4 x 10-5


Buffer Problems

Calculate the pH of a solution containing

0.50 M HQ in 0.10 M NaQ: Ka = 4.0 x 10-5


Drill

Calculate the pH of a solution containing

0.30 M HZ in 0.10 M NaZ: Ka = 3.0 x 10-5


Lab requirements
Lab Requirements

  • To make accurate measurements, we must have solutions with accurately measured concentrations


Standard solution
Standard Solution

  • A solution with known concentration

  • 2.004 M HCl


STD Problems

Calculate the mass of KHP (MW = 204.23) required to make 1.0 L of 0.100 M KHP


Henderson-Hasselbach Eq

[A-]

[HA]

pH = pKa + log


Henderson-Hasselbach Eq

[B+]

[B]

pOH = pKb+ log


Buffer Problems

  • Calculate the salt to acid ratio to make a buffer solution with pH = 5.0

  • Ka for HBZ = 2.0 x 10-5


Buffer Problems

Calculate the salt to base ratio to make a buffer solution with pH = 9.48

  • Kb for MOH = 2.0 x 10-5


Calculate the HCO3- to H2CO3 ratio in blood with pH = 7.40

  • Ka1 for H2CO3 = 4.4 x 10-7


150 ml of 0.10 M NaOH is added to 100.0 ml of 0.10 M H2CO3. Calculate all.

  • Ka1 for H2CO3 = 4.4 x 10-7

  • Ka2 for H2CO3 = 4.7 x 10-11


ad