Juliana Park Mayumi Tamada CHEM 111B LAB/ M-F 1-4PM 15 August 2012 Spectroscopy Lab Introduction In this lab, the molar absorptivity of the complex FeLn2+ will be determined by using the absorbance of the complex and its concentration. The absorbance will be found by using a spectrophotometer. For the next part of the lab, the formula of the complex will be determined by also using the volume of ligand and the absorbance again. Experimental There are two different parts to the experiement. In the first part, five 100 mL flasks of 5 mL ligand solution, 5 mL 2 M sodium acetate, 4 mL 3 M NH2OH, and 1-5 mL Fe2+ solution are diluted with water.
Then 5mL of HCl was added to copper to completely remove all traces of zinc. Once the bubbling had stopped, the rest of the liquid was decanted away from the copper. Then the copper recovery set up was put together using tubing, Buchner funnel, filter paper and suction flask. Then the filter paper was weighed before placing it in the funnel and wetted down. The aspirator was turned to medium high, and then the copper was poured onto wetted filter paper.
The purpose of this lab is to focus on how to make zinc iodide in a different way using compounds instead of elements, which are barium iodide and zinc sulfate. We will see if the reaction between these two compounds will occur and make a prediction by writing a chemical equation. The procedures for this lab are to place a small test tube inside a 50mL beaker and weigh it. Then, using a spatula, add 0.45±0.03 g of zinc sulfate heptahydrate into the small test tube and record the mass. After that, dissolve the sample in 2 mL of deionized water and shake the test tube for 1 to 1 ½ minutes to dissolve the solid.
Add the HCl SLOWLY to the magnesium by running it down the side of the beaker. Adding the acid too quickly will result in the spattering of the acid. Write down any observations of the reaction. 6. After all the acid has been completely added and the reaction has stopped, use a pipette to add a few extra drops of acid into the beaker until the reaction stops.
To properly remove the brain the embalmer took a hook and pulled as much of the brain out that was possible through the nose. After this was completed the brain was put in water to dissolve, and according to who you talked to and what they believed the water was either thrown out or carried to the burial chamber to be left with the pharaoh or whoever. The fourth step was probably the most important step to be done right to be able to go into the afterlife. This step was the removal of the internal organs. The liver, lungs, stomach, and the intestines all had to be removed.
Experiment 3: Copper Cycle Purpose Statement In the experiment 3, I need to synthesis a number of copper compounds and need to recover copper metal. Before I can synthesis a number of copper compounds and recover copper metal, I need to collect all the observation, physical properties and solutions through the copper cycle, after that I can synthesis a number of copper compound. When I can synthesis a number of compound I can recover copper metal by weighting an empty weighing bottle and solutions from above experiment (copper that I collect from the copper (I) compound experiment and copper cycle). Data Table Table 3.1: Reagents used in the copper cycle and in the preparation of copper (I) solids Reagent | Appearance | Volume (mL) or Mass (g) | Concentration (M) | Cu(NO3)2 | Light blue, transparent | 10.0 mL | 0.10 | NaOH | Clear (colourless), transparent | 20.0 mL | 2.00 | HCl | Clear (colourless), transparent | 40 drops ~ 1.3 mL | 6.00 | NH3 | Clear (colourless), transparent | 50 drops ~ 1.7 mL | 6.00 | H2SO4 | Clear (colourless), transparent | 15.0 mL | 1.50 | Zinc dust | Silver, solid, very thin layer, shiny | 0.14 g | N/A | Ethanol | Clear (colourless), transparent, odour (alcohol) | 5.0 mL | N/A | CuCl2 • 2H2O | Green,
I chose this picture because it gave a very detailed and captured all of the important things in the first draft of the Emancipation Proclamation. 25.Holford, David M. Lincoln and the Emancipation Proclamation in American History. Berkeley Heights, NJ: Enslow Publishers, 2002. This book briefly describes the thinking behind the Emancipation Proclamation and its
We first separated each of the isotopes into their rightful groups and then proceeded to count the amount of pieces for each isotope. We then weighed one of each isotope on a scale to get the mass. In order to find the percentage of abundance we divided the number of particles of the isotope by the number of particles in the sample. To find the average atomic mass of Candium is calculate by multiplying the mass of the isotopes by the percentage of abundance, then adding the products. Data: Isotope | M & M’s | Skittles | Reece’s Pieces | Number of Particles | 35 | 27 | 49 | Mass (g) | 0.85g | 1.03g | 0.74g | Calculations: Percentage of abundance: Reece’s: 49/111= 0.44 x 100= 44% Skittles: 27/111= 0.243 x 100= 24.3% M & M’s: 35/111= 0.31 x 100= 31% Average Atomic mass: (44 x 0.74g) + (24.3 x 1.03g) + (31 x 0.85g)= 83.94g Conclusion: Candium had three isotopes, Reece’s Pieces, Skittles, and M & M’s.
al.). Some pollutants – for instance, polycyclic aromatic hydrocarbons – can lead to life-threatening diseases in humans and wildlife, such as cancer (Harvey). Scientists use many different methods to remove these pollutants from water supplies; one of those methods is the utilization of adsorption onto a porous substance, normally charcoal. Due to numerous circumstances, scientists have begun searching for alternatives to charcoal, one of them being Bentonite clay. However, Bentonite clay cannot be easily removed from the water, so in this project the students were instructed to modify the clay to make it magnetic and then compare its effectiveness in absorbing a model PAH against charcoal.
Because all forensic scientists are required to have their DNA in CODIS Toxicology Lab: Where is vitreous humor normally located? In the eyes How is a maggot milkshake used? The maggots feed on decomposing bodies so when the maggots are mashed up and tested the results come out with the DNA of the person they were feeding on Why do toxicologists analyze so many different body fluids? Because looking at multiple fluids helps confirm results Who invented Forensic Toxicology? Paracelsus What is the name of the document you signed the evidence out on?