Determination of Partition Coefficient

Introduction

Diffusivityordiffusion coefficientis a proportionality constant between themolar flux due to moleculardiffusion and the gradient in the concentration of the species (or the driving force for diffusion). Diffusivity is encountered inFick’s law and numerous other equations ofphysical chemistry. It is generally prescribed for a given pair of species. For a multi-component system, it is prescribed for each pair of species in the system.The higher the diffusivity (of one substance with respect to another), the faster they diffuse into each other.This coefficient has anSI unit of m2/s (length2/ time). In CGS units it was given in cm2/s.

In this experiment, agar gel is used as the diffusion medium. The gel consists of the semi-solid network of agar molecules interpenetrated by water which form the continuous phase for diffusion. The agar molecular network prevents the speed up of water molecules movement which occurs naturally such as through the convection flow of water caused by temperature difference.

Objective:

  1. To determine the D value (diffusion coefficient) at different temperature, concentration and solvent/medium.
  2. To determine the radius and volume of the particle.
  3. To determine the mass of particle and molecular weight of substance

Methodology

  1. Molten agar solution is prepared by boiling the powder in an appropriate solvent.
    1. 200 mL 2% agar in Ringer solution.
    2. 50 mL 1% agar in Ringer solution.
    3. 50 mL 2% agar in Ringer solution.
  1. 10 mL of the molten agar is poured into specified test tubes and left to solidify.
    1. 2% agar in Ringer into 14 test tubes.
    2. 1% agar in Ringer into 2 test tubes.
    3. 2% agar in distilled water into 2 test tubes.
  2. The reference mixtures is prepared for Crystal Violet and Bromothymol Blue by mixing:
    1. 5 mL of the molten 2% agar in Ringer with 5mL, 1 in 500,000 Crystal Violet solution.
    2. 5 mL of the molten 2% agar in Ringer with 5mL, 1 in 500,000 Bromothymol Blue solution.
    3. 5 mL of the molten 1% agar in Ringer with 5mL, 1 in 500,000 Crystal Violet solution.
    4. 5 mL of the molten 2% agar in distilled water with 5mL, 1 in 500,000 Crystal Violet solution.
  3. 3 mL of the following solution is filled into specified test tubes containing the solidified agar. Each test tube is covered with aluminium foil and the time is noted.
    1. 1 in 200 Crystal Violet into 4 tubes containing 2% agar in Ringer.
    2. 1 in 400 Crystal Violet into 4 tubes containing 2% agar in Ringer.
    3. 1 in 600 Crystal Violet into 4 tubes containing 2% agar in Ringer.
    4. 1 in 400 Crystal Violet into 2 tubes containing 1% agar in Ringer.
    5. 1 in 400 Crystal Violet into 2 tubes containing 2% agar in distilled water.
    6. 1 in 400 Bromothymol Blue into 2 tubes containing 2% agar in Ringer.
  4. Test tube 4(i), (ii), (iii) is kept in an incubator at 370C. The rest of the test tubes is kept at room temperature.
  5. The distance between the origin (the solution or gel interface) to the point of a known concentration (the point where the colour is equivalent to the appropriate reference mixture) is measured accurately at 900s, 1800s, 2700s, 3600s, 4500s, 322200s and 415800s.
  6. The result is recorded and tabulated.

Results

a) 1 in 200 Crystal Violet (CV) in 2% agar in Ringer at room temperature.

Tube 1

Tube 2

b) 1 in 200 CV in 2% agar in Ringer incubated at 37°C

Tube 3

Tube 4

c) 1 in 400 CV in 2% agar in Ringer at room temperature.

Tube 5

Tube 6

d) 1 in 400 CV in 2% agar in Ringer incubated at 37°C

Tube 7

Tube 8

e)1 in 600 CV in 2% agar in Ringer at room temperature.

Tube 9

Tube 10

f) 1 in 600 CV in 2% agar in Ringer incubated at 37°C

Tube 11

Tube 12

g) 1 in 400 CVin 1% agar in Ringer at room temperature.

Tube 13

Tube 14

h) 1 in 400 CV in 2% agar in distilled water at room temperature.

Tube 15

Tube 16

i) 1 in 400 Bromothymol blue in 2% agar in Ringer

Tube 17

Tube 18

Calculation

Calculations were conducted to determine:

  • the D value,
  • the radius of the molecule,
  • the volume of the particle,
  • the mass of the particle, and
  • the molecular weight of the substance

Equations used,

1. To determine the D value

*of which, x2 is y and 2.303(4)(D)(t)(log10m0-log10m) is (mx+c)

Representing the equation of straight line y=mx + c. In calculating the D value, the value of c (y-intercept) = 0, thus the new equation isy=mx.

Based on 2 equations to find the slope of the line, m;

and

D value is calculated as such,

Modified to,

2. To determine the radius of the molecule

The radius is calculated as such,

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

a) 1 in 200 Crystal Violet (CV) in 2% agar in Ringer at room temperature.

Tube 1

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

Tube 2

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

b) 1 in 200 CV in 2% agar in Ringer incubated at 37°C

Tube 3

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

Tube 4

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

c) 1 in 400 CV in 2% agar in Ringer at room temperature.

Tube 5

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

Tube 6

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

d) 1 in 400 CV in 2% agar in Ringer incubated at 37°C

Tube 7

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

Tube 8

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

e) 1 in 600 CV in 2% agar in Ringer at room temperature.

Tube 9

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

Tube 10

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

f) 1 in 600 CV in 2% agar in Ringer incubated at 37°C

Tube 11

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

Tube 12

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

g) 1 in 400 CV in 1% agar in Ringer at room temperature.

Tube 13

1. Determining D value

2. Determining the radius of the molecule

3. To determine the volume of the particle

4. To determine the mass of the particle

5. To determine the molecular weight of the substance

Tube 14

1. Determining D value

2. Determining the radius of the molecule

Cite This Work

To export a reference to this article please select a referencing stye below:

Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.

Order a Unique Copy of this Paper

Essay Creek is an academic writing service provided to you by, a London-based company.

  • Experience
    Helping students successfully for 11 years.
  • Confidentiality & Security
    Be sure your information will be kept confidential due to our secure service.
  • Quality & Reliability
    8.5 out of 10 average quality score according to our customers' feedback. 97.45% of orders delivered on time.
  • Versatility
    478 active writers in 68 disciplines.
  • 100% money back guarantee
    You can always request a refund if you are not satisfied with the result.

Read more about us

Our team of writers is comprised of people with necessary academic writing skills and experience in various fields of study.

  • Skilled writers only
    We carefully choose writers to employ, paying attention to their skills and abilities.
  • Competence
    Your order will be assigned to a competent writer who specializes in your field of study.
  • In-depth knowledge
    Our writers know both peculiarities of academic writing and paper formatting rules.
  • Motivation
    We keep updated on results our writers show, motivating them to constantly improve their performance.

Read more about our writers

  • Testimonials
    Our clients' testimonials prove we're doing everything right.

Check for yourself

  • Sample essays
    The best way to understand how well our writers do their work is to view sample essays written by them.

View samples

  • Our Free Essay Tools
    Even more opportunities to improve your academic papers.


Bibliography Generator
Words to Pages Converter
Words to Minutes Converter
College GPA Calculator
Thesis statement generator