The silver colloidal particles obtain a negative charge because of to the adsorbed citrate ions; The absorption peak was observed at about 420nm which is the typical characteristic absorption peak for Ag nanoparticles. UV absorption peak of chitosan-Ag nanoparticles was observed by other researchers in the range 410–450
The Benedict’s test is useful for reducing sugars. Reducing sugars are a carbohydrate that can either be straight chains with an aldehyde group at the end or as ring forms with a ketone group (Hill, 1982). Monosaccharides and most disaccharides will reduce copper (II) sulfate. The Benedict’s solution contains cupric ions and the aldehyde groups at the end of the sugars will reduce the cupric ions to cuprous ions (Cu+). There will be a precipitate of copper (I) oxide when the cuprous ions combine with oxygen (Hill,
In this experiment, method 1 generate a mixture of yellowish crystals and a yellowish gluey product. Using method 2, the product appear as white crystals. Given that the yellow color remain throughout the product in method 2, too much aldehyde was added. It was predicted that this was the source of error because aldehyde was a yellow liquid. In this experiment, 293 mg of aldehyde was weighted for method 1 instead of 250 mg and.
TLC was used to identify the actual unknown product as well as other products/reactants present in the filtered solution. The procedure was conducted by placing a TLC plate in a developing chamber that is filled with a small amount of solvent. The solvent cannot be too polar because it will cause spotted compounds on the TLC plate to rise up too fast, while a very non-polar solvent will not allow the spots to move. The polarity of the spots also determines how far it moves on the plate; non-polar spots are higher than polar ones. After spots on the TLC form, the Rf values are calculated and used to analyze the similarity of the compounds.
Since the solvent is nonpolar, we would expect carotene to have the lowest Rf, then xanthophylls, and chlorophylls would have the highest. As discussed before, this is because chlorophylls are the most polar of the three and carotenes are the least polar of the three. Based on my results, I would say that the packing and running of the column was effective in separating the pigments as there were quite different Rf values for the original than for the other two colors and the band for the yellow was nothing like the bands for the green. There were no limitations in procedure which negatively affected the end results, so there is nothing I would change to it going
Instead of using a simple benzene derivative as a reactant, the substrate being used is ferrocene, which consists of a central iron atom bounded or sandwiched between two cyclopentadienyl rings. This synthesis also involves greener reagents. As stated above, aluminum chloride is often used as a strong Lewis acid catalyst to start the reaction. However, it is corrosive and can give off considerable quantities of acidic and toxic wastes. Since ferrocene is highly reactive (due to its two cyclopentadienyl rings), AlCl3 can be replaced with a more benign catalyst, phosphoric acid.
This creates a cube-shape and makes what we know as table salt. The bond that forms water molecules is called a hydrogen bond. It takes the positively charged hydrogen from water and bonds it with the negative charge of the oxygen in another water molecule. This may create a weaker bond than a covalent bond but it is strong enough to affect the atoms involved. Hydrogen bonds help determine the three dimensional shape of the molecules.
Red and black phosphorus are considerably more passive in chemical reactions. The oxidation of white phosphorus occurs through a chain reaction. The oxidation of phosphorus is often accompanied by chemiluminesce; an occurrence whereby light is emitted during a chemical reaction and not producing significant quantities of heat. Phosphorus combines directly with all halogens. When heated with metals, phosphorus forms phosphides.
This helps to indicate whether or not the reaction follows Markovnikov’s Rule, which states that the electrophile (E+) will add to the carbon involved in a double bond that produces the most stable carbocation. If the rule is followed, the reaction will proceed according to the mechanism in Figure 1. In the silver nitrate test, the alkyl bromide is added to AgNO3. The rate of precipitation with 2° should be faster than the solution with the 1° alkyl halide. In the sodium iodide test, the alkyl halide is added to sodium iodide in acetone.
Arizona, Idaho, and Nevada are the largest silver producing states. Silver-107 and silver-109 are two natural occurring isotopes. Silver is from ores that have small amounts of metal. Their can either be a lot of silver in one or a little bit of silver. Mining is mostly how silver is found, and is produced after the primary metal has been removed,where the remaining waste contains silver.