High Concentration Lab

As the Concentration of the Sucrose Solution decreases, the more the potato’s mass increases. This is due to the solution being hypertonic. So, as the solute concentration gets lower, the potato’s water concentration will get higher, therefore more water particles from the solution will absorbed by the potato. Some changed very little in mass because the concentrations of the H2O molecules in the potato and outside the potato were equal. This equality in concentration is called Isotonic.

Read in your lab manual about the following agar mediums: Blood Agar (pg 168), EMB Agar (pg 170), Mannitol Salt Agar (MSA)(pg 172) ), MacConkey Agar (pg 174), and PEA Agar (pg 176) to answer the following:

The following hypothesis was made in regard to effect of the concentration gradient on the rate of diffusion: The higher the concentration gradient, the faster the rate of diffusion.

On the other hand, diffusion occurs when particles in the water move from high concentration to low concentration. I also to seek to

Van’t Hoff’s Law suggests that the osmotic potential of a cell is proportional to the concentration of solute particles in a solution. The purpose of this experiment was to determine if there are any differences between the osmolalities, the no-weight-changes of osmolalities, and the water potentials of potato cores in different solutions of different solutes. The percent weight change of the potato cores was calculated through a “change in weight” method. The potato core’s weight was measured before and after they were put into different concentrations of a solute for 1.5 hours. In our experiment, there were no significant differences from the osmotic potentials of our results and the osmotic potentials of other scientists work. Ending with chi square values of 2.17 and 2.71, and p values of 0.256 and 0.337, concluding that there is no difference in water potentials of potato cores in different solutions of different solutes at varying concentrations.

In conclusion, the potato cube with the highest surface area to volume ratio (the 1x1x1 cube) had the fastest rate of diffusion as it had the largest percentage increase in mass. While all the other cubes of potato had larger increases in mass at face value compared to the smallest cube, the smallest cube had the largest overall gain in percentage. The results support my hypothesis that the smallest cube will have a higher rate of osmosis because it has a proportionally larger amount of surface area compared to its volume.

One milliliter of 6.00-M phosphoric acid was placed into a 125-mL Erlenmeyer flask using a volumetric pipette. Using a slightly larger pipette, six milliliters of 3.00-M sodium hydroxide was transferred into a 50-mL beaker. Then a disposable pipette was used to slowly mix the sodium hydroxide into the phosphoric acid while the solution was swirled around. Then both the beaker and flask were rinsed with 2-mL of deionized water and set aside. A clean and dry evaporating dish was weighed with watch glass on a scale. Then the solution was poured into the dish and the watch glass was placed on top. The solution was then heated with a Bunsen burner to allow for the water to boil off to reveal a dry white solid. After the dish cooled to room temperature it was once again weighed and the new mass was recorded.

Diffusion is the transfer of molecules from an area that has a higher concentration to an area that has a lower concentration. Osmosis is the diffusion of water. The purpose of this experiment was to study the process of osmosis. In order to test osmosis, eggs that had been soaking in vinegar were taken and placed in four beakers of solution with different levels of glucose. Using this experiment we were able to determine the rate of osmosis of different solutions, with various amounts of glucose, through eggs. In the results of this lab it was found that the eggs were either hypertonic or hypotonic and that the

Discussion: This lab shows ‘diffusion’ of agar cube. The agar contains high concentration of solute (phenolphthalein) and the sodium hydroxide has lower concentration of solute (phenolphthalein). So as the phenolphthalein in the agar cube diffuses out to the sodium hydroxide, which turns the color of liquid, the sodium hydroxide diffuses into the agar cube that turns the color of agar cube as well.

Water can diffuse into or out of a cubicle. The emplacement of the high concentration of water determines which direction the water diffuses. If there is a higher concentration of water molecules in the cell, osmosis will happen and the urine will run out of the cell, resulting in the cell becoming smaller. On the other hand, if there is a higher concentration of urine in the cell’s environment, the cell will expand because of the assimilation of water through osmosis. The various liquids in these experiments exhibit how diffusion flows from fields of a higher concentration of a substance to a lower absorption.

Purpose: To identify how the surface area and the volume of the Agar cube relates to the percent diffusion whether it increases or

Agar quality: this could be resolved by always using new individually made agar that is created with the plastic covering over all the agar or all sized that were exposed to the edge are cut off during the cutting process. This would ensure that the entirety of the agar cube is permeable and not non permiable. HUMAN ERRORS: Cutting the agar: the agar can be created individually and placed into perfect moulds insuring that the perfect size was consistent across all

The stearic acid is obtained from animal fats. The molecular formula is C17H35COOH and its composed of a hydrophilic acid group, COOH, and a hydrocarbon chain C17H35. The long hydrocarbon chain is like lubrication oil, because it does not have any affinity for water. In other words, when the stearic acid becomes in contact with water it doesn’t mix in water. The hydrophobic chain floats upwards in a vertical position in the solution. (ChemSkills) When the stearic acid was dropped to the water it spreads across the surface until it creates a monolayer, a one molecule thick layer. The volume of stearic acid was calculated by determining the number of drops used to create the monolayer on the dish by using the following equation:

According to the research work on a high viscous binder detergent granulation system of LAS (high viscosity binder) and zeolite carried out by Rough et al (2005), they found that at a higher impeller speed, size distribution had the same peak modal diameter, a narrower peak width and less vol% of bigger granule diameter. Comparing findings from Rough et al (2005) detergent granulation with pharmaceutical granulation of lactose and PEG melt (low viscosity binder) carried out by Schaefer et al (1993), Schaefer et al (1993) reported a larger peak modal diameter and a narrower size distribution at higher speed. Heng et al (2000) suggested that at higher impeller speed with increased shear forces, rate of granule consolidation should increase as surface plasticity and

The characteristics of the biochar derived from pine fruit residue are shown in Table -1. The adsorptive properties of sorbent are greatly dependent on their particle size and distribution throughout the mass. Effective size and uniformity coefficient are the two important parameters for treatment of contaminated water using adsorbent as filtering media in column operation where control of particle size is critical. The effective size corresponds to the sieve size through which 10% of the material will pass, and the uniformity coefficient is the ratio of the sieve size that will just pass 60% of the material to the effective size. Generally, the rate of adsorption get enhanced as the particle size decreases due availability of increased surface area. Therefore, the adsorbent with smaller effective sizes provide better adsorption capacity due to better the access to the surface area and faster the rate of adsorption. The typical range of effective size and uniformity coefficient for activated carbon as adsorbent media practiced satisfactory is D10 = 0.15-0.35 mm and Cu = 2-3 respectively. In our case, Table 1 shows that the biochar prepared have an effective size of 0.055 mm and uniformity coefficient 2.87. The more uniform adsorbent media is expected to provide the slower head loss buildup and therefore, careful consideration of particle sized distribution is must for dynamic column design.