Saturday, November 13, 2010

Between windex and clorox window spray, which is less harmful to the environment?

Hypothesis: If 1 mL of both clorox window cleaner and windex are placed in two different petri dishes with microbes in them, then the clorox window cleaner will kill more microbes than the windex because clorox is more harmful to the environment.

Materials:
  • 3 petri dishes
  • pond water full of microscopic life
  • 1 microscope
  • 1 bottle of windex
  • 1 bottle clorox window cleaner
  • 1 graduated cylinder
  • 1 pipet
  • 1 buret

Procedures:
  1. Fill the three petri dishes with pond water and look at each under a microscope. Count the total sum of microscopic life in each dish and record the results.
  2. Place 1 mL of windex into one of the petri dishes.
  3. Repeat step 2 for the clorox window cleaner in another petri dish.
  4. Over the next few days, record the number of the amount of living organisms in each dish.

Data:


Windex
Clorox
Control
Day 1
36
33
29
Day 2
31
28
29
Day 3
27
22
28
Day 4
23
17
28
Day 5
19
11
27
(Numbers are the total number of living organisms in each dish.)

Conclusion:
Based on the data, the windex petri dish experienced a decrease in life of 47.22%, and the clorox dish experienced a decrease of 66.67%. While the controlled variable dish, with nothing in it, experienced a drop of only 6.9%. My hypothesis was correct: clorox is more harmful to the environment. The validity of this lab could have been improved in several areas however. When calculating the number of living organisms, some estimation was required. The amount of life in the controlled variable, as well as the others, may have gone down because the petri dishes were kept in a room with low temperature. Using the information in this lab, people can now make a decision on what window cleaner to use that will cause less harm on the environment.