Investigating the Concentration of Iron (III) Thiocyanate Research Question: To determine the optimal effect (equilibrium condition) of manipulating the concentration of both reactants on the values of absorbance detected by a spectrophotometer at 540 nanometers, in between the forward reaction of Iron (III) Chloride (FeCl3) and Potassium Thiocyanate (KSCN). Background Information: I’m an IASAS theatre tech alternate and my main role is being the assistant stage manager, which puts me in charge of handling props as well. It was quite engaging for me to find a reaction that created a chemical replica of hemoglobin; especially after our recent production: The Complete Works of Shakespeare. Thus, it was interesting to find an equal solution …show more content…
DV Color Change This cannot be measured directly, as the color change occurs too quickly to have any actual measurement. However, the color change is measured by measuring the final solution’s absorbance with a Genesys 20 spectrophotometer set at 540 nanometers. Controlled Wavelength of absorption Genesys 20 Spectrophotometer was manually set to a wavelength of 540 nm. I used 540 nm by taking the average of 510 and 570 nm (UV-Visible Spectroscopy) after researching the optimal wavelength to use for a dark red solution. As there was no exact value given, I took the average between the most mentioned intervals. Length of time reaction occurs before measuring Each reaction was allowed 1 minute of reaction time before being placed into cuvettes. (UV-Visible Spectroscopy) Volume of reactants The initial volumes of each reactant was kept constant at 20 cm3 through every manipulation, in order to decrease uncertainty and chances of error. Equipment used Same Spectrophotometer will be used. Method/Procedure: Equipment and Reagent …show more content…
So, we’ll be going from 0.5 to 0.4, 0.3, 0.2, 0.1 mol/dm3 accordingly for each reactant, while the other reactant stays a constant 0.5 mol/dm3. a) For each manipulation, we’ll be conducting 4 trials, so prepare 4 cuvettes and their lids ahead of time. 3) Make sure your gloves, safety goggles and apron are on before proceeding further. Let’s say we’re manipulating concentrations for Iron (III) Chloride and the first manipulation is to react 0.4 mol/dm3 FeCl3 and 0.5 mol/dm3 KSCN. 4) Use a 25 cm3 graduated cylinder for the initial measurements of each solution. Pour 20 cm3 of 0.5M FeCl3 and 20 cm3 of 0.5M KSCN in separate graduated cylinders. 5) Using a 10 cm3 graduated cylinder, pour the necessary volume of distilled water, in this case 5 cm3. After pouring the distilled water to the graduated cylinder containing the FeCl3. 6) Next, prepare a 50 cm3 beaker, and pour both reactants into it. Wait for at least 1 minute to allow the reaction to reach completion. Procedure—Post-dilution 1) Use a pipette to fill 3/4 of each cuvette with the new solution from the beaker. Repeat until you have 4 cuvettes with the same solution. 2) Put a lid on each cuvette in order to prevent
While the solution dissolved, 50 mL of distilled water was added to a 150 mL beaker and heated on the hot plate. When the solution started to boil 2.65 grams of Na2SiO3*5H2O was added to the beaker with a stir bar and heated to a gentle boil. When both solutions began to boil, the sodium silicate solution was slowly added to the sodium aluminate. The solution was kept at 900C for 60 minutes and stirred with stir bar. After 60 minutes, the zeolite solution was cooled for 5 minutes and for the magnetized zeolite , 0.78 grams of FeCl3 and 0.39 grams of FeSO4*7H2O was added to the flask and stirred until the iron parts dissolved.
Question 4: List the 3 errors; • Adding too many drops of NaOH at the same time would affect the results because we can’t determine the exact equivalent point when the color changed. The results won’t be accurate and that will affect all the data that are dependent on the amount of NaOH to titrate. • Other error could be the hardness to notice a color change; we always use a white paper under the flask to determine when the color changes right away. And if we don’t use the white paper it will be hard to determine the color change and the amount of NaOH that was used to titrate it. • Also other source of error could be by not rising the burette with NaOH before we fill up with it, or it maybe they were rinsing it with a lot of NaOH which could affect the data recording for NaOH amount of titration.
This is what I will mix with the varying amounts of Strontium nitrate to form the precipitate. • Strontium Nitrate (enough to fill 8 boiling tubes with your varying amounts/36cm³) This is what I will mix with the sodium carbonate in order to form my precipitate. • Test Tube Rack
Next, about 10 mL of both solutions, Red 40 and Blue 1, were added to a small beaker. The concentration of the stock solution were recorded, 52.1 ppm for Red 40 and 16.6 ppm for Blue 1. Then, using the volumetric pipette, 5 mL of each solution was transferred into a 10 mL volumetric flask, labelled either R1 or B1. Deionized water was added into the flask using a pipette until the solution level reached a line which indicated 10 mL. A cap for the flask was inserted and the flask was invented a few times to completely mix the solution. Then, the volumetric pipette was rinsed with fresh deionized water and
Step 2: Mix both test tubes , shake gently and time the reaction. Step 3: The same step as procedure 1, and step 3 which is to record the observed color step 4: use the palette/color chart to help you identify the observations you make. Safety precautions: Pull your hair back Safety eye goggles Closed toe
In the round-bottom flask (100 mL), we placed p-aminobenzoic acid (1.2 g) and ethanol (12 mL). We swirled the mixture until the solid dissolved completely. We used Pasteur pipet to add concentrated sulfuric acid (1.0 mL) to the flask. We added boiling stone and assembled the reflux. Then, we did reflux for 75 minutes.
Fill the well with 90ml dh20 to reach 100ml. move 10 ml of the second well to the third well. FIll the third with another 90ml dh20 to reach 100ml. Move 10 ml of the third well to the fourth well. Fill the fourth well with 90ml dh20 to reach 100ml.
Jaspreet Singh Professor Paratore Biology 1 November 1, 2014 Spectrophotometry Identifying Solutes and Determining Their Concentration Statement of the Exercise or of the Problem The purpose of the lab experiment was to attain the following objectives: • Learning to Operate the Spectrophotometer • Construct absorption spectra for cobalt chloride and chlorophyll. Hypothesis If greater and higher concentrations of cobalt chloride are added to each solution then greater amounts of light would be absorbed by each solution. Thus a liner relationship will result in which the absorbance of a substance would be proportional to its concentration, which will be depicted, in a linear graph.
Note: make sure that you leave space between distillation take-off and the cylinder. This would allow you to observe the drops of the distillate that enter to Graduated Cylinder. Step 2: Begin distillation.
In the separating funnel, the liquid was left on the retort stand for ten minutes to settle. The cover of the separating funnel was removed.
Dependent The time taken for the bluish -black color to fade away (color of Iodine solution mix with starch solution ). The rate of enzyme reaction Minutes (min) Table 1.1 – Table shows the controlled variables in the experiment variables Units Measures of controlled variables.
Use these results to determine the product concentration, using Beer-Lambert’s Law: A= ɛCl (where A is the absorbance, ɛ is the molar absorptivity, C is the product concentration and l is the length of solution that the light passes through). Calculate the product concentrations at every minute for 10 minutes for all 7 of the test tubes using Beer-Lambert’s Law. Plot a graph of product concentration vs. time and then use the gradients of the 7 test tubes to determine the velocities of the reaction. After calculating the velocities, plot a Michaelis-Menten graph of velocity vs. substrate concentration.
The solution with the pigments was spotted 15 times on both region A and region B and then allowed to dry. When the plate was dry it was placed into the tank for at least 20
Once dissolved, fill the rest of the volumetric flask up to the line on the neck of the flask. Again mix the solution. Use four, 10mL volumetric flask, and label them from 1-4. Add approximately 2mL of copper sulfate pentahydrate into flask 1, 4mL to flask 2,
The 250 mL beaker was rinsed well with the distilled water. The titration procedure above was repeated 2 more times with fresh potassium acid