In this lab we used two processes called Diffusion and Osmosis. Diffusion is the movement of molecules from areas of high concentration to areas of low concentration. Diffusion is a process that requires no energy and involves smaller non-polar molecules. In Figure 1 you can see the molecules spreading throughout the glass from the area of high concentration, so that the areas with low concentration are filled evenly as well. The other process was osmosis. Osmosis is the diffusion of water through a membrane from an area of high contraction to an area of low concentration. Osmosis happens in three different environments. Osmosis is like diffusion in it requiring no energy. Osmosis can happen in three different types of environments; Hypertonic, Isotonic and Hypotonic. If osmosis were to …show more content…
Each group was assigned a different percent of sucrose solution out of the four variables; 0% , 5%, 10%, and 15%. After we filled the beaker we then got two potato cores. Once we had the cores we cut the skin off the ends. Following this we then cut the two potato cores into four 2.00 cm potato cores. After they were cut into 2.00 cm each we found the mass. We zeroed out the scale and weighed all four potato cores at once and recorded the mass. We then put those potato cores into the beaker of 75 mL of solution. With the potato cores in the beaker we then put a watch glass over the top of the beaker to minimize the amount of solution that evaporates. We let the potato cores sit in the solution overnight. The next day we then emptied the beaker of the solution by carefully draining the solution, while not letting the potato cores fall out. We then took the potato cores out of the empty beaker and dabbed them lightly with paper towel to get any excess solution off. We did this quickly and following it we then took the mass of all four potato cores again and recorded
Now, they are ready to start the lab. The empty crucible is weighed by and the weight was recorded. Then the students used a disposable pipet and put close to 4.0 grams of their milk sample in their crucible on the scale. The crucible was then placed back on
Additionally, it was difficult obtaining a piece of rhubarb that was thin and particularly red, therefore the effect could not be best observed in the cells. Part B: Design your own experiment Parts of this practical were taken and slightly altered from the following link http://www.markedbyteachers.com/gcse/science/investigate-the-effect-of-surface-area-on-osmosis-in-potato-tissue.html Aim: To observe the effect different surface area: volume ratios have on osmosis in potato tissue. Hypothesis: If the potato has a larger surface area: volume ratio, the quicker osmosis will take place and the larger the mass will be at the end of the experiment, therefore the difference in mass of the potatoes from the start of the experiment to the end of the experiment will be larger. Additionally, the potato pieces left in a saltwater solution will decrease in mass, whereas the pieces left in water will increase in mass.
Exploration Title: Effect of Temperature on rate of Osmosis Submitted By: Abdulkarim Kamal Date Submitted: October 19th 2015 Subject: Biology HL Teacher: Mr. Nick Aim: This is an investigation to determine the relation between temperature of a solution (sucrose) and the rate of osmosis Scientific Context: Osmosis is defined a passive transport process in which a fluid diffuses across a semi-permeable membrane, from an area of high solute concentration to an area of low solute concentration and vice-versa. There are various factors that could potentially influence the rate of osmosis; these factors include volume, concentration, and temperature. If all external factors that may interfere with rate of osmosis are controlled, the results will show equal amounts of fluid on both sides of the barrier (membrane); this is known as an “isotonic” state.
The items that were massed were the evaporating dish, watch glass, and NaCO3. The materials were massed once before and once after being heated in the drying oven. The mass of the evaporating Dish before was 46.57 g; while after being heating was 60.15 g. The mass of the watch glass before was 57.97 g and after was 48.75g. There were two masses taken for the substance NaHCO3- one with the evaporating dish and one without, subtracted out after the lab was concluded. The mass of the substance with the dish was 48.79 g before and 62.33 g after; meanwhile, the mass of the substance without the dish was 2.22 g before and 2.18 g after. The mass of the NaHCO3 had changed after the reaction occurred along with after it was placed on the hot plate and being in the drying oven.
The Study of Diffusion and Osmosis Using Deshelled Eggs Maquita A. Dieufene Jessica Thelwell(Partner) 10/09/2014 1611 Evening Lab Introduction It is quite simple to overlook the roles diffusion and osmosis play in daily life. If one has ever spent too much time in the pool and watched as their fingers begin to turn prune-like, that is an example of osmosis. Osmosis is simply defined as the movement of a concentrated solvent through a semi permeable membrane to a more concentrated solvent.(Biology Corner) Relating to the earlier example of osmosis, your body acts as the more concentrated solvent for the water to penetrate. Diffusion is the exact opposite of osmosis.
The objective of the lab was to understand the Law of Conservation of Mass. The Law of Conservation of Mass states that matter can be changed from one form into another, mixtures can be separated or made, and pure substances can be decomposed, but the total amount of mass remains constant. For example, from our experiment in the lab, we observed mass of the mixture of aqueous Sodium Sulfide and aqueous Zinc chloride turned white color. After the filtration, and all the water was evaporated, we measured the mass very close to what we had started at the beginning. The error in mass occurred because of the remained residue (solute) in the beaker.
A larger sample size could have enabled averages to be resulted, and the experiment could have had several trials until concordant results are attained to increase the reliability. To enhance the accuracy of the results, a machine such as a cheese wire to cut straight along the edge could have been employed that would more accurately cut the cubes and hence reducing human error. This would be efficient as there is a large chance of human error when cutting the cubes by hand as the agar is slippery. Cubes with different sizes could be observed to improve the validity of the experiment. The weight of the bottom of the cubes pushing against the beaker likely caused an error to occur.
In this lab when looking at cells, we observed the salinity and osmolarity of the cell when placed in the environment. With the different concentrations of NaCl, we are able to see how different environment can constrain an organism and see the wide range of responses to regulate in cell’s osmolarity. The cells we studied was sheep red blood cells (erythrocyte), because they are the most studied membrane system and therefore used as ideal membrane to study the relationship between water and the passing of the different concentration of NaCl across the membrane. The purpose of the experiment was to observe the cell and infer which direction of the flow of the water due to the cell volume change.
My hypothesis was correct. The raisins increased in mass because of the absorption of the water. The mass of the raisins before they were put in the warm water was 2.69 grams. The mass of the raisins after were put in the warm water was 3.13 grams. The mass of the raisins increased .44 grams during the process of osmosis.
Diffusion and Osmosis Lab Report By: Jettica Williams BIOL 1107 Lab September 21, 2016 Prepared for Mrs. Fulford Lab Course Page Break The cell membrane act as a roadblock for cells. The cell membrane has a very hectic job. It restricts the access to what comes in and what goes out. The bond the membrane shares with others is the idea of accountability.
Osmosis Lab Report Research Question: How does the change in the concentration of a sucrose solution affect the process of osmosis in a potato cell by measuring its mass? Background information: 1 Osmosis is the process by which a liquid passes through a semi-permeable membrane, moving from an area with a high concentration of water to a low concentration of water. There are various factors that affect osmosis such as: concentration, surface area and temperature. The concentration of solutions can affect the rate of osmosis, as there is more difference in the concentration of the solutions, which means osmosis, will take place quicker. Surface area could affect osmosis based on the ease by which molecules can get through the semi-permeable
Fat in chips: • First we wieghed out 10 g of crushed chips • We then put them in a beaker • Next we poured 50ml of pentane on it • We mixed them with a spatula • We then filtered the mixture through a funnel and glass wool to get rid of the chips (into a florence flask) • Before the destillation process we measured the florence flask and the cork ring • Through the destillation process we managed to separate the pentane and the oil • We weighed the oil with the flask and the cork ring and subtracted the mass of the flask and cork ring to get the mass of oil • We then recorded our results Salt in popcorn: • We again weighed out 10 g, but of crushed popcorn this time • Which we put into a beaker ( which we had already weighed beforehand)
IV. Data and observations Mass of beaker (g) 174.01 Mass of beaker + NaOH pellets (g) 174.54 Mass of NaOH pellets 0.53 TRIAL 1 TRIAL 2 Mass of potassium acid phtalate (KHP) (g) 0.15 0.15 final buret reading (ml) 30.75
The percentage weight change is dependent on surface area of potato Controlled The amount of salt solution used Percentage of salt in solution Length of time the potato is sat in water Materials needed 3 Potatoes 600 ml 15% salt solution Utensils 4x 300 ml beaker Knife Cutting board Scale Ruler Procedure 1. 8 rectangular prisms will be cut from the potatoes;
This experiment is to investigate the relationship between solute concentration and the movement of water through semipermeable membrane by the process of osmosis. The purpose of this The Visking tubing apparatus establishes the osmosis procedure. The Visking tubing is a semipermeable membrane filled up with concentrated sucrose solution. The surface of the semipermeable membrane symbolizes the visking tubes and the mixture demonstrates the cytoplasm. If the Visking tube is absorbed in water, after a period of time, it will be have water inside water, this is because the water molecules can pass through the tubing, while the larger sugar molecules cannot diffuse out from the tubing because the size of sugar molecules do not allow it to go through the tubing.