Unit 2: Practical scientific procedures and techniques
Learning Aim A: Undertake colorimetry to determine concentrations of solutions
Aims:
To find the absorptivity of unknown sample solutions using data from
colorimetry.
To prepare own concentration of copper sulfate solution by weighing
hydrated copper (II) sulfate solid CuSO4.5H20 dissolving in water making up
to an accurate volume.
Use a colorimeter to accurately determine concentrations of sample A and
B, which are two different concentrations of copper (II) sulfate (CuSO4)
solution.
A colorimeter is a apparatus used for measuring the absorbance of light passing
through a liquid in a cuvette. The device measures the intensity/concentration of
the colour that develops upon introducing a specific reagent into a solution.
Colorimetry is used in various industries. For instance, a colorimeter can be used
to monitor the growth of a bacterial or yeast culture. Colorimetry can also be
used in industries such as colour printing, textile manufacturing, and paint
manufacturing.
What is colorimetry?
Colorimetry is a scientific technique that is use to determine the concentration of
coloured compounds in solutions through measuring absorbance of light using a
colorimeter and applying the Beer-Lambert law A = ebc
What is a colorimeter?
,A colorimeter is a apparatus used in colorimetry that measures the absorbance of
wavelengths of light by specific solutions.
Making a standard solution
Equipment:
Scale
Weights
Hydrated copper (II) sulfate
Weighing boat
Distilled water
Glass stirring rod
Funnel
Volumetric flask
Measuring cylinder
Cork
Method:
1. Calibrate the scale for weighing the mass.
, 2. Measure 12.475 grams of hydrated copper (II) sulfate into a weighing boat.
3. Pour into a beaker and wash the weighing boat with distilled water.
4. Use a stirring rod to dissolve the solid in the water, the solution will turn
blue.
5. Wash the glass rod with distilled water.
Wash the glass rod several times to ensure that all remaining solid is removed
from the glass rod to the beaker.
6. Pour the liquid from the beaker to the 100ml volumetric flask through a
funnel to prevent spilling the solution.
7. Rinse around the edges of the beaker into the volumetric flask.
8. Continue to fill the volumetric flask up to the 100ml line.
Make sure that the curve of the meniscus is level with the marked line at 100ml.
9. Place a cork on top of the volumetric flask. Invert the flask to mix and label.
Inverting the volumetric flask at least ten times allow the liquid to properly
homogenize.
Learning Aim A: Undertake colorimetry to determine concentrations of solutions
Aims:
To find the absorptivity of unknown sample solutions using data from
colorimetry.
To prepare own concentration of copper sulfate solution by weighing
hydrated copper (II) sulfate solid CuSO4.5H20 dissolving in water making up
to an accurate volume.
Use a colorimeter to accurately determine concentrations of sample A and
B, which are two different concentrations of copper (II) sulfate (CuSO4)
solution.
A colorimeter is a apparatus used for measuring the absorbance of light passing
through a liquid in a cuvette. The device measures the intensity/concentration of
the colour that develops upon introducing a specific reagent into a solution.
Colorimetry is used in various industries. For instance, a colorimeter can be used
to monitor the growth of a bacterial or yeast culture. Colorimetry can also be
used in industries such as colour printing, textile manufacturing, and paint
manufacturing.
What is colorimetry?
Colorimetry is a scientific technique that is use to determine the concentration of
coloured compounds in solutions through measuring absorbance of light using a
colorimeter and applying the Beer-Lambert law A = ebc
What is a colorimeter?
,A colorimeter is a apparatus used in colorimetry that measures the absorbance of
wavelengths of light by specific solutions.
Making a standard solution
Equipment:
Scale
Weights
Hydrated copper (II) sulfate
Weighing boat
Distilled water
Glass stirring rod
Funnel
Volumetric flask
Measuring cylinder
Cork
Method:
1. Calibrate the scale for weighing the mass.
, 2. Measure 12.475 grams of hydrated copper (II) sulfate into a weighing boat.
3. Pour into a beaker and wash the weighing boat with distilled water.
4. Use a stirring rod to dissolve the solid in the water, the solution will turn
blue.
5. Wash the glass rod with distilled water.
Wash the glass rod several times to ensure that all remaining solid is removed
from the glass rod to the beaker.
6. Pour the liquid from the beaker to the 100ml volumetric flask through a
funnel to prevent spilling the solution.
7. Rinse around the edges of the beaker into the volumetric flask.
8. Continue to fill the volumetric flask up to the 100ml line.
Make sure that the curve of the meniscus is level with the marked line at 100ml.
9. Place a cork on top of the volumetric flask. Invert the flask to mix and label.
Inverting the volumetric flask at least ten times allow the liquid to properly
homogenize.
