Lab Report Sample

ADVERTISEMENT

Name___________________________________________Period______Entry #_______
This is an example of a good Lab Report
Martha Hughes
st
1
period
August 17, 2007
The effect of soap on number of drops
(It should contain the IV and DV)
Purpose:
The purpose of this lab is to explore how soap added to water will affect its cohesion
ability.
Hypothesis:
If soap affects the cohesion of water, then adding soap will decrease the number of drops
that can be placed on a penny.
Background Information:
One of the properties of water is cohesion. This refers to the ability of water
molecules to stick to one another. This is also the reason that “water striders” can walk on
the top of the water without falling through. Water also has other properties that create
versatility with the compound such as “capillary action”, or the ability of water to travel
upwards against gravity. Water also has a high specific heat and can absorb a large
amount of heat energy before a temperature change takes place.
Soap is a surfactant, which is a “chemical agent that is capable of reducing the
cohesion of the liquid in which it is dissolved”. Surfactants, therefore, reduce cohesion
between water molecules and break the hydrogen bonds. When soap is added to water,
the individual water molecules will break apart and disperse.
Materials:
1. plain water in a cup
2. soapy water in a cup
3. one penny
4. pipette
5. paper towels
6. safety goggles
Procedures:
1. Obtain necessary materials.
2. Put on safety goggles and tie back hair.
3. Fill the pipette with plain water and drop slowly onto the penny while counting
the number of drops. Record. Repeat 2-3 times and record each time.
4. Repeat step #3 with soapy water. Be sure to record everything.
5. Clean excess water with paper towels, then clean and return everything to its
proper place.

ADVERTISEMENT

00 votes

Related Articles

Related forms

Related Categories

Parent category: Education
Go
Page of 2