Introduction The goal of this lab was to analyze the iron content in both iron tablets and cereal. The methods used to achieve this goal included using spectrometry to set a calibration curve and measure iron content within the mixture of cereal and the iron tablet. The absorbance of the mixtures were used in conjunction with the calibration curve to measure the amount of iron content in each. Experimental First the calibration curve was made by preparing a mixture of Fe (NO 3) 3 and KCSN with HNO 3. The five molar HNO 3 was diluted to one molar HNO 3 using the formula M 1 V 1 = M 2 V 2.
One hundred milliliters of. 001 M Fe (NO 3) 3 and. 1 M KCSN both in HNO 3 were prepared by measuring out. 0403 grams of Fe (NO 3) 3 and.
972 grams of KCSN and putting each in a flask and filling that flask to 100 ml with HNO 3. After these solutions are prepared 1. 0 ml of the iron nitrate was placed in a 250 ml beaker with 100 ml of the KCSN solution. A dry cuvette was filled with 1. 0 M HNO 3 and placed in the spectrometer and the instrument was zeroed. The cuvette was then rinsed out.
The solution that was previously prepared is then put into the cuvette and put in the spectrometer and the absorbance is measured. The solutions must be poured back into the original flask in order to maintain a constant volume. Next another 1. 0 ml of iron nitrate was added to the 100 ml of KCSN solution and put in the cuvette. The absorbance was measured again and recorded. This procedure was repeated until 10 ml of iron nitrate were used in the solution.
Generally, there are two ways in preparing a solution, one is by dissolving a weighed amount of solid in a required solvent and the other is by dilution of a concentrated solution into the desired concentration. In diluting concentrated solution, the concentration of the diluted solution can be determined by standardization. To standardize a solution, we will need to perform titration. In this ...
After all the absorbencies were recorded the graph was plotted with iron nitrate concentration on the horizontal axis and absorbance on the vertical axis. To extract the iron from the cereal, first the 32. 0 grams of cereal were placed in a plastic bag and crushed until the particles were very small. Next, 30. 0 grams were weighed out and placed in a 600 ml beaker with 250 ml of deionized water and a Teflon magnet.
The beaker was the placed on a stirring plate and was stirred for fifteen minutes. The beaker was then removed from the stirring plate and the magnet was removed. The magnet was then rinsed off and placed in a 600 ml beaker with 50. 0 ml of 1. 0 M HNO 3. The beaker was warmed and swirled until no iron was visible on the magnet.
The magnet was then removed and rinsed with 2 ml of 1. 0 M HNO 3. The magnet was then placed in the slurry again and was placed on the stirring plate for another 15 minutes. The magnet is then rinsed again and placed in the 600 ml beaker and warmed and swirled until no iron was visible on the magnet.
After the third extraction, the solution in the 600 ml beaker was poured into the 100. 0 ml volumetric flask. The magnet and beaker were then rinsed with 10 ml of 1. 0 M HNO 3 three times, each wash was placed into the volumetric flask. Then the solution was diluted to the mark with 1. 0 M HNO 3.
The absorbance of this solution was measured identically to the iron nitrate solution. One milliliter of cereal sample was placed in 100 ml of. 10 M KCSN in 1. 0 M HNO 3 and put into a cuvette to measure the absorbance. The iron tablet extraction was performed by first placing an iron tablet into a 25 ml Erlenmeyer flask. Twenty milliliters of 5 M HNO 3 were then added and the flask was placed on a hot plate.
After ten minutes the flask was then removed and the tablet was crushed with a glass rod. The crushed tablet solution was then heated for ten minutes. The liquid was then filtered into a 100 ml volumetric flask, adding 4 portions of 15 ml deionized water into the solid atop the filter paper. Next the solution was diluted to the mark with deionized water.
Introduction: The way to get the full results of this lab was through the process of osmosis. Osmosis is the movement of water across a membrane into a more concentrated solution to reach an equilibrium. When regarding cells osmosis has three different terms that are used to describe their concentration. The first of these words is isotonic. Cells in an isotonic solution show that the water has no ...
This solution is then filtered again and 1 ml of this solution was placed into a 10 ml volumetric flask and diluted to the mark with 1. 0 M HNO 3. One milliliter of the solution was then placed in 100 ml of. 10 M KCSN in 1. 0 M HNO 3. The solution is then measured for its absorbance and recorded.
Calculations Standard Deviation formula (‘O (Xi – X avg) ^2) ^ 1/2 (n-1) ^ 1/2 M 1 V 1 = M 2 V 2 Concentration = (M of Element in stock solution) (Volume of Stock solution) Volume of total solution Absorbance A = ebc Results and Discussion y = 1 E-05 x-1 E-05 R squared = 1 According to the calibration curve the concentration for the cereal is 2. 8 E-5 m/L. This was discovered by using the average number for the absorbance and using the calibration curve to match up the concentration. The same method was used to find the concentration of the iron tablet.
The concentration of the iron tablet was 1. 5 E-5 m/L. The errors that may have occurred would be due to inexact measurements of iron nitrate solution. The smallest amount would alter the amount of absorbance because of its high concentration. The recommended daily intake of iron is 18 milligrams or 3. 22 E-4 moles.
According to this experiment the cereal provides 2. 85 E-5 moles or iron which is significantly below the recommended daily value. The iron tablet only yields 1. 5 E-5 which is even lower than the cereal. In the body iron combines with hemoglobin and is responsible for the transport of oxygen. This is due to the strong attraction between iron and oxygen.
The body cannot use all of the iron which enters the body because it would be too hazardous. In the experiment the dissolution of the iron tablet was not as it would be in the body because the acid in the human stomach has a pH of 2 where the pH of 5 M HNO 3 is not as corrosive. Conclusion The amount of iron that was found in cereal and the iron tablet were drastically lower than the recommended daily value. In addition, conditions in the body are very different from those in the experiment because of efficiency, difference in acids and their strength and time as well..
The Essay on To investigate the effect to the potato cells in the different solute concentration water
Water can move through the different cells due to the difference of water potentials in the cells. If there is a higher solute concentration in the cell than outside the cell, the water will move into the cell. However, if the concentration of inside the cell is lower than the outside, water will not move into the cell. This process is called osmosis. Research question; This investigation will ...