How to Calculate the Percent of Oxygen in the Air
- 1). Fill the beaker with water until it is approximately half full.
- 2). Grip the steel wool with the forceps.
- 3). Within the fume hood, rinse the steel wool with acetone for 30 seconds. Dry the wool with a paper towel.
- 4). Dip the steel wool in the more concentrated acetic acid. Dry it off with a second paper towel.
- 5). Dip the steel wool in the more dilute acetic acid. Shake it off, but do not dry it completely.
- 6). Insert the wool into the graduated cylinder.
- 7). Invert the cylinder and lower it into the beaker. Immediately note the level of water in the cylinder. This level will change as the wool reacts with the air's oxygen.
- 8). Note the water's final level.
- 9). Divide the change in water level by the original level. For instance, if the water originally reached the 80 milliliter mark, indicating 80 milliliters of air, and it rises by 17 milliliters: 17 / 80 = 0.2125 = a 21.25% oxygen concentration.
- 10
Repeat the experiment several times and find the average of your oxygen percentage estimates.
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