Properties of Water Lab
STATION 1: (20 pts)
Property: Cohesion / Surface Tension
Cohesion is the ability of water molecules to stick to themselves (H-bonds). Surface tension is a property of water
created by cohesion that enables a drop of water to keep its shape.
1. Predict how many drops of water will fit on the surface of a penny before it spills
over______________.
2. Put drops of water (one at a time) on the top of the penny until the water spills over the edge. Record your
data in the table below. Include the data of all your group members then calculate the average.
Illustrating the Surface Tension of Water
Person 1
Person 2
Person 3
Person 4
Person 5
AVERAGE
3. Adding surfactant to the surface will reduce the surface tension of water causing it to lose its shape and
spread out.
Predict how many drops of water will fit on the surface of a dry penny after it has been smeared with a
surfactant__________________________.
4. Place one drop of soap on your finger then spread it on the surface of a dry penny.
5. Put drops of water (one at a time) on the top of the penny until the water spills over the edge. Record your
data in the table below. Include the data of all your group members then calculate the average.
Effect of Surfactant on Surface Tension
Person 1
Person 2
Person 3
Person 4
Person 5
AVERAGE
STATION 2: (5 pts)
Property: Water is a Universal Solvent
A solvent is something a substance is dissolved into. Complete the following test to see if water really does
dissolve substances better than any other liquid.
1. Measure 50 mL of water and put in cup A. Measure 50 mL of rubbing alcohol and put into cup B.
2. Place 1 spoonful of salt in each of the cups at the same time.
3. Use the stir rod to swirl contents in the cup at least 3 times.
4. Observe for 1 minute then record the data below using the key shown.
Substance
Key
Cup A (water)
Cup B (alcohol)
++ 100% dissolved
+ partially dissolved
-did not dissolve
