BIOLOGY LAB REPORT-OBSERVING OSMOSIS
Aim: The aim of the experiment is to observe osmosis by the help of the selective membrane of egg. Osmosis is the diffusion water from an area with a high water concentration to an area with a lower concentration.
Research question: What is the effect of in different concentration of solutions with respect to movement of water through egg’s external membrane.
Hypothesis: If I put an egg in %30 Salt Solution, because of the different concentration areas egg will get smaller as we increase concentration because water tends to move from high concentrated are to low concentrated area. (Amount of water)
• Dependent Variables: Mass change of eggs
• Independent Variables: Concentration amount of solute in water.
• Constant Variables: Time
• Control Variables: initial mass of eggs, temperature
Procedure: We took our equipment such as beaker, paper towel, beaker, electronic balance, plastic spoon and 150 ml 30% salt solution (each group has different solutions.) Before this process we had to decalcify the eggs. In this experiment it is really important to decalcify the eggs to remove outer shell and to reach the semipermeable membrane of the eggs since the main aim of the experiment is to observe osmosis thorough a semi permeable membrane. Leaving the eggs in vinegar for 72 hours does decalcification. After recording the initial masses after getting the eggs, each group measured the mass of eggs after 8 minutes and repeated the process for 4 times. At the end groups concluded the experiment with 4 different masses different than the initial mass.
Data Table A: Egg in Distilled Water
Time (minutes±1s) Mass (grams±0,01g) %Mass Change
Initial Mass: 79.08g
In: 8:50 Out: 8:58 After 8 min. 79.16 0.10%
In: 9:01 Out: 9:09 After 16 min. 79.55 0.58%
In: 9:12 Out: 9:20 After 24 min. 79.88 1.25%
In 9:21 Out: 9:29 After 32 min. 80.19 1.40%
Data Table B: Egg in 15% Salt Solution