2. To determine the densities of water, an unknown liquid, a rubber stopper, and an unknown rectangular solid.…
When holding test tube inverted over heptane flame, condensation formed against top walls of the test tube. When the burning splint was added the walls of the test tube became less foggy from the condensation formed from the heptane flame.…
.2400 grams of the unknown compound. This is done in duplicate and purple-tinted precipitates are placed in Gooch crucibles. The precipitates are suction dried using ethyl alcohol then acetone to…
Reactions were then incubated at 30°C for 10 minutes, and then placed on ice for 5 minutes. After incubation and cooling, the absorbances of the various samples were analyzed via spectrophotometry, and the final…
then used a spectrophotometer to get the absorbance reading over time, and we used these readings to…
3. Preapre the computer for data collection by opening “Exp 30” from the Chemistry with Computers experiment files of LoggerPro. The vertical axis has absorbance scaled from 0 to 0.35. The horizontal axis has scaled from 0 to 20 minutes.…
Chelex Extraction and PCR Amplification of the Amelogenin Gene For The Purpose of Gender Determination. Abstract The amelogenin gene is a protein involved in the development of the enamel matrix. It is located on both the X and Y chromosomes in humans and can be used as a way to distinguish between males and females.…
Preparation In a dry round bottom flask, 1.5mL of cyclohexanone was added with 5mL of methanol. The solution was cooled in an ice bath for 3 minutes after which 0.2g of sodium borohydride was measured and added to the solution. Upon mixing, a gas was formed (bubbles). The round bottom flask was removed from the ice bath and placed at room temperature.…
The gaseous hormone ethylene has been shown to influence a diverse array of plant growth and developmental processes, thus it is critical for plants to optimize the ethylene production at developmental transitions as well as during stress response. Ethylene is derived from the amino acid methionine, which in the first step is converted to S-adenosyl-methionine (AdoMet) by AdoMet synthetase3,4. The 1-Aminocyclopropane-1-Carboxylic acid Synthase (ACS) catalyzes the conversion of AdoMet to 1-aminocyclopropane-1-carboxylic acid (ACC)5, which is the rate-limiting step in ethylene biosynthesis. ACC is then converted to ethylene by ACC oxidase (ACO), a member of the oxygenase/oxidase superfamily of enzymes6.The ACS plays a central role to regulate ethylene production through changes in ACS gene expression levels and the stability/activity of the enzyme. ACS proteins can be divided into 3 groups (type-1, 2 & 3) based on their C-terminal domain and the presence of phosphorylation sites. Type-1 and -2 ACS isoforms contain phosphorylation sites for kinases, but type-3 lacks of the phosphorylation sites.…
By examining the pond water with the 100X lens, the student was able to differentiate and classify 1) the cyanobacteria: nostoc due to its distinctive S shape and beads with surrounding cells, 2) two nematodes (phylum nematoda) parallel to one another (the nematodes appeared as slender worms, colorless, and encompassed of cells), and 3) the cyanobacteria: anabaena, which was blue-green in its feature with long filaments of cells (resembling a seaweed structure).…
Before the coloured solution was measured for its absorbance, deionized water was first placed in the ultraviolet-visible (UVV) spectrophotomter as to calibrate the UVV spectrophotometer to zero. Then only some of the diluted solution in the volumetric flask was transferred into a cuvette cell using a dropper and its absorbance was measured and recorded. After…
There are three different major types of spectroscopy techniques covered in our practical, which includes Ultraviolet-Visible Light Spectroscopy, Infrared Spectroscopy and Atomic Absorption Spectroscopy & Atomic Emission Spectroscopy. The use of spectrophotometry in the analysis of chemicals quantitatively and qualitatively is common, since they’re readily available and generally easy to operate, at the same time giving fairly accurate and consistent results. The choice of instrument depends on the wavelength region of choice, which in turn depends on the nature of analyte, either they are coloured or can be changed into coloured derivatives; whether they contains functional group that absorbs light in the UV or Infrared region; or even other absorbing species that depends on the analyte present in the same phase.…
Learn to use trigonometry techniques programmed in EXCEL for calculating engineering type formulas to determine the altitude of an actual flight of a Level 2 rocket that the students have built in the Lab. A 2-angle (observer) technique will be used as taught in previous Lab to get the observed altitude.…
Matter is anything that has mass and takes up space(volume). Mass is a body of matter with no definite shape or size. A physical change is a change that doesn’t involve a change in the substances chemical identity. A physical change is one that commonly includes changing between the states of solid, liquid, and gas. The physical changes that occurred in the lab would include: mass of steel wool, ice and water, and the dissolved sugar. A chemical change is one that involves a reaction and can’t be brought back to normal after the change is done. A chemical change results in the formation of a new chemical substance. The chemical changes that occurred in the lab would include: sodium carbonate and calcium chloride, burning steel wool, and dissolved Alka-Seltzer. The system is the chemical reaction that happens and the surroundings are what goes on around the reaction. When we mixed the sodium carbonate and the calcium chloride during the lab, the chemical reaction that was going on when we mixed them was the system; everything around it was the surroundings. The definition of the law of conservation of mass is: matter cannot be created nor destroyed, only its form can change. In the lab, we burned a wad of steel wool. After being burned it appears that the mass of the wool is shrinking but really it is just changing form. If you gathered all of the bits after the burning of the wool, they would combine to equal the same mass that the wool originally weighed. Examples of possible error in the lab could have been that the scale wasn’t super accurate and the weight measures could have been off. Another error could have been that people didn’t accurately poor the right amount of chemical into the vial.…
G H Jeffery, J Bassette, J Mendham, R C Denny. Vogel 's Textbook of Quantitative Chemical Analysis 5th edition. Longman Scientific and Technical; 1989. Chapter 17, colorimetry and spectrophotometry; p. 645-651…