Problem Statement
Plan and design an investigation to find out if black ink from 4 different brands of permanent
markers contains the same dyes. However, the markers are insoluble in water.
Hypothesis (2 marks)
Example: Different brands of markers contain the same dyes in their black ink.
Aim (2 marks)
Related to hypothesis and problem statement. Method to be used should be specified.
Example: To separate the dyes in different brands of black ink using paper chromatography
Apparatus and Materials (2 marks)
All essential ones stated. These should also be reflected in the procedure.
Example:
filter paper, 4 different brands of black markers, beaker, ruler, pencil, wooden splint, alcohol as
solvent
Procedure (4 marks)
Logical sequence of steps written in present or future tense, workable or feasible to test
hypothesis.
Example:
1.
2.
3.
4.
5.
6.
Fill the beaker with 30 ml of alcohol.
Cut rectangular strip of filter paper 2 cm x 8 cm.
Draw a line 1 cm from the end of the filter paper, using a pencil.
Using 1 of the markers, place a dot in the middle of the line drawn.
Attach the opposite end of the filter paper to the wooden splint.
Partially immerse the tip of the filter paper closer to the ink spot in the beaker with the
alcohol.
7. Record your observations.
8. Allow the filter paper to dry.
9. Repeat the procedure for the remaining 3 markers and ensure that the dot is the same
size for each marker.
10. Tabulate the results and calculate the retention factor of each of the markers.
Variables (3 marks)
Example:
Manipulated Variable: Different brands of markers
Responding Variable: Retention factor
Controlled Quantities: Volume of alcohol and size of dot
Expected Results (2 marks)
Observations, measurements or qualitative data which will prove or disprove the hypothesis. If
a table is used, then the data for the responding variable should be left blank.
Example:
Table showing the retention factor for the different brands of markers.
Marker Brand
A
B
C
D
Retention Factor
Treatment of Results (2 marks)
Shows link between how data to be collected proves or disproves hypothesis.
Example:
If all 4 brands of markers have the same retention factor, then it contains the same dyes, and
the hypothesis is supported. If not, then the hypothesis is not supported.
Assumptions/Limitations/Precautions (3 marks)
Any combination of these 3 stated.
Example:
The alcohol used may be an inefficient solvent for the different markers.
The size of the ink dot may vary depending on the brand.
The length of filter paper used may not be sufficient to separate all components.
20 marks (scale to 10)