Dissolving Oxygen Lab Report

Glory Nguyen

October 20, 2015

Period G

Dissolving Oxygen

Introduction In this lab, you will be testing the levels of oxygen in water samples with different temperatures and water samples exposed to different light distances. This will show us where the most oxygen is produced, which is where most of the organisms are. The relationship between oxygen and carbon assimilation is when oxygen is being produced the the photosynthesis plants, they release oxygen. In turn, it is then being inhaled by an organism that needs oxygen, releasing carbon as carbon fixation. So more carbon means more oxygen being released. The concentration of dissolved oxygen is obviously a lot higher during the afternoon, this is when the sun is out and where photosynthesis

Record the temperature of the cold water sample onto Table #1

Immerse the test tube under the cold water and stop in with a rubber stopper (while under water).

Remove the rubber stopper and add 6 drops on Winkler's solution #1 up into the test tube with cold water.

Then add 6 drops of Winkler's solution #2 into the test tube with cold water.

Place the rubber stopper back on the test tube with cold water; careful for spillage.

Invert the test tube with cold water several times to mix the solution (brown precipitation will form).

Allow the precipitate to settle for 5-10 minutes.

Repeat steps 2-8 with the room temperature and warm temperature samples.

Remove the stoppers and add 6 drops of concentrated sulfuric acid to each of the test tubes.

Put the rubber stoppers back on the test tubes and invert them; this dissolves the brown precipitate to a yellowish-amber solution.

Then titrate each of the fixed water samples. *In the case that you don't know how to titrate, refer to the bottom of the page.

Method/ Procedure (for Part