A student used chromatography to separate the different photosynthetic pigments in a chlorophyll solution - AQA - A-Level Biology - Question 1 - 2023 - Paper 2
Question 1
A student used chromatography to separate the different photosynthetic pigments in a chlorophyll solution. She had the following materials.
Chromatography paper
A r... show full transcript
Worked Solution & Example Answer:A student used chromatography to separate the different photosynthetic pigments in a chlorophyll solution - AQA - A-Level Biology - Question 1 - 2023 - Paper 2
Step 1
Draw line/origin on (chromatography) paper (using ruler and pencil)
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The student should start by using a ruler and pencil to draw a straight line near the bottom of the chromatography paper. This line serves as the origin point for the pigments and must be clearly marked.
Step 2
Add chlorophyll solution to origin line
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Using a pipette or dropper, the student should apply a small amount (approximately 2 cm³) of the chlorophyll solution directly onto the origin line drawn on the chromatography paper.
Step 3
Add solvent A below the line
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Next, the student should prepare a beaker with solvent A and carefully place the chromatography paper in it, ensuring that the solvent does not cover the origin line where the chlorophyll solution was applied. This will allow the solvent to move up the paper and separate the pigments.
Step 4
Remove/stop from glassware before solvent reaches end of chromatography paper
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Once the solvent has traveled an appropriate distance (but before it reaches the end of the paper), the student should remove the chromatography paper from the glassware. This will effectively stop the separation process.
