equilibria between different phases
Download
Skip this Video
Download Presentation
Equilibria between different phases

Loading in 2 Seconds...

play fullscreen
1 / 11

Equilibria between different phases - PowerPoint PPT Presentation


  • 109 Views
  • Uploaded on

Equilibria between different phases. Advanced Higher Unit 2b(ii). Separating Funnel. Separates immiscible liquids with different densities Usually water, plus an organic solvent (ether, chloroform). [solute](organic). K =. [solute](aq). Partition Coefficient.

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 'Equilibria between different phases' - tim


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
equilibria between different phases

Equilibria between different phases

Advanced Higher

Unit 2b(ii)

separating funnel
Separating Funnel
  • Separates immiscible liquids with different densities
  • Usually water, plus an organic solvent (ether, chloroform)
partition coefficient
[solute](organic)

K =

[solute](aq)

Partition Coefficient
  • When a solute is added to two such immiscible liquids, some will dissolve in each layer
  • The distribution will not be even
  • Ratio of distributed called PARTITION COEFFICIENT
solvent extraction
Solvent extraction
  • Partition coefficient is used in solvent extraction and for purification
  • For example, with an impure carboxylic acid, the acid will dissolve in ether but impurities will not
calculation
Calculation

Consider the following partition coefficient of an organic acid:

[acid](ether)

K =

= 5

[acid](aq)

If 10g of acid is dissolved in 100ml of water and 100ml ether, the quantity of acid which can be extracted can be calculated...

slide6
x / 100

= 5

(10 – x) / 100

x

= 5

(10 – x)

x

= 50 – 5x

6x

= 50

x

= 8.3 g

[acid](ether)

K =

= 5

[acid](aq)

Concentration organic acid (ether) = x / 100

Concentration organic acid (aq) = (10 – x) / 100

an alternative method
An alternative method
  • Repeat the previous calculation, but this time for using 100 ml water and 50 ml ether for a first extraction, then repeating with another 50 ml ether for a second extraction
slide8
[acid](ether)

K =

= 5

[acid](aq)

x / 50

= 5

(10 – x) / 100

Concentration organic acid (ether) = x / 50

Concentration organic acid (aq) = (10 – x) / 100

x

= 5

(10 – x) / 100

50

x

= 50 – 5x / 100

50

100x

= 50 – 5x

50

2x

= 50 – 5x

7x

= 50

x

= 7.14 g

slide9
[acid](ether)

K =

= 5

[acid](aq)

x / 50

= 5

(2.86 – x) / 100

Concentration organic acid (ether) = x / 50

Concentration organic acid (aq) = (2.86 – x) / 100

x

= 5

(2.86 – x) / 100

50

x

= 14.3 – 5x / 100

50

100x

= 14.3 – 5x

50

2x

= 14.3 – 5x

Total extracted:

7.14 + 2.04 = 9.18g

7x

= 14.3

x

= 2.04 g

chromatography
Chromatography
  • Method of separation which depends on the partition of substances between two phases
  • One is mobile, the other is stationary
    • Stationary phase – depends on type of chromatography
      • Paper
      • Thin layer
      • Column
      • Gas/liquid
      • High performance liquid
slide11
Task
  • Each group take one of the chromatography types and prepare a one page notes sheet for the class and for the Think-chemistry website
ad