Laboratory surface tension
In this laboratory you will study the density of substances, the surface tension properties of water and the structure and function of surfactants.
Laboratory guidance
Material:
Lighter • 1 beaker/bowl/glass • 1 paper clip/staple/hairpin (of metal) • washing-up liquid (ideally, e.g. YES or Ajax) • H2O
Method:
1. Fill the beaker/glass/bowl with enough water that it almost overflows.
2. Place the paperclip/hairpin/staple on the surface of the water so that it floats (repeated attempts may be required). One tip is to use a paper clip that you "fold out" and use instead of your fingers when placing the paper clip/hairpin/staples on the surface of the water.
3. Place the match on the surface of the water.
4. While the objects are now floating on the surface of the water, carefully drop a drop of washing-up liquid into the water. Study what is happening.
Now you must write a report on the laboratory you did.
Make sure you include all headings that should be included in a lab report:
Introduction
Purpose
Material
Method
Results
Discussion - both results and method analysis
Source list
Source criticism
Feel free to repeat how to write a laboratory report.
However, keep in mind that you must include a source reference in the introduction and discussion and a complete list of sources at the end of the assignment.
If you feel unsure about the difference between source reference, source list and source criticism, you must repeat the teaching about this at the beginning of the course.