Osmosis Lab Report

Osmosis Lab Report

Introduction The reason of this experiment was to identify the properties and effects of osmosis. Osmosis can be defined as the diffusion of water through a selectively permeable membrane. (Miller/Levine) Osmosis occurs when there is an area of higher and lower concentration. Osmosis is a type of diffusion. Diffusion is when molecules move from an area of higher concentration to an area of higher concentration. The three types of concentrations are hypotonic, hypertonic, and isotonic.

When in comparison to another solution, a hypertonic solution has a lower concentration, a hypertonic solution has a higher concentration, and an isotonic is when the two solutions have an equal concentration. The experiment tested the relationship between the concentration of an egg and solutions of different concentrations. The hypothesis is that an egg placed in distilled water will gain mass while an egg placed in syrup would lose mass. Methods To perform the experiment gloves and safety goggles were obtained. Two decalcified eggs were also obtained from the teacher.

Using an electronic scale, the initial mass was measured and recorded of each egg. One egg was then placed in a beaker of distilled water while the other was placed in a beaker of syrup. After a time lapse of ten minutes, each egg was taken out and dabbed to remove excess liquids. After excess liquids had been removed, they were placed on the scale one at a time. The mass was then recorded in a data table. These steps were repeated in ten minute intervals four more times, each time recording the mass in the data table.

After all measurements were collected, the percent of mass change was calculated using the formula listed below: 100(Mass after Immersion-Initial Mass) Initial mass Results After the fifty minutes soaking in the solution, the egg placed in water gained mass (Table 1) while the egg placed in syrup lost mass after fifty minutes (Table 2). The percent of mass change was calculated and put onto a graph (Graph 1) Discussion The hypothesis that the egg in water would gain mass was proved correct by this experiment.

When the egg was placed in the water, the egg was hypertonic and the water was hypotonic. During the fifty minutes water diffused through the egg to higher concentration, the egg. As the water went into the egg it gained mass. If the egg was left in the water for a longer period of time, it would have continued to gain mass until the concentrations were equal, or isotonic. The hypothesis also stated that the egg in syrup would lose mass. This was also correct. When the egg was in the syrup, the syrup was hypertonic making the egg hypotonic.

To equal out the concentration, the water inside of the egg diffused to the syrup which weakened the concentration of the syrup and strengthened the concentration of the egg. As the water left the egg the mass lowered. If the egg was left in the syrup, the mass would have continued to get lower until isotonic concentrations were reached. There were many opportunities for possible error. During the measuring of the mass, excess liquid was removed. If not all liquid was removed then the measurement would not necessarily be accurate.

Also the amount of water and syrup put into the beakers wasn’t exactly measured. There could have been a drastically different amount in one group’s beaker compared to another. Another source of error was if an egg wasn’t entirely decalcified, then there might have been left over shell which contributed to the mass. In the future, there could be a predetermined amount of time you wipe down the egg, a common measure of liquids, and a certain amount of time that the egg sits in the vinegar. To further this experiment, different types of syrup could be tested compared to water.

Different syrups could contain different molecule make up. They could contain more or less sugar. The difference between sugar-free and non-sugar-free could also be tested for further this experiment. If an egg is soaked in different types of syrup then the one with less sugar will gain mass and the one with more sugar will lose mass. Works Cited Miller, Kenneth Raymond, and Joseph S. Levine. Prentice Hall Biology. Boston: Pearson/Prentice Hall, 2008. Print. Table 1. The percent of mass change of an egg placed in distilled water. Mass| % Mass Change| Initial| 89. 9| 0%| After 10 Minutes| 90. 4| 0. 56%| After 20 Minutes| 91. 3| 1. 56%| After 30 Minutes| 92| 2. 34%| After 40 Minutes| 92. 5| 2. 89%| After 50 Minutes| 93. 1| 3. 56%| Table 2. The percent of mass change of an egg placed in maple syrup. | Mass| % Mass Change| Initial| 79| 0%| After 10 Minutes| 79| 0%| After 20 Minutes| 78. 6| -. 51%| After 30 Minutes| 78. 6| -. 51%| After 40 Minutes| 78. 1| -1. 14%| After 50 Minutes| 77. 7| -1. 65%| Graph 1. The percent change in mass of each egg versus time.