Mass Spectroscopy: Unknown Compound's Molecular Weight And Formula

The objective of this lab was first to convert the mass of a compound to the number of moles and number of molecules and then determine the concentration of salt and its component. The first thing we did was get the mass of an empty container by using a scale and it came out to be 16.87g. Next thing we did was pick a substance which in this case it was Potassium Chloride and placed it on the scale to get a total mass of 31.20g. The container the Potassium Chloride was in only had a mass of 16.87g which means that the mass of the substance was 14.33g. To convert the mass to the number of moles we took the amount of the substance 14.33g and divided it by the mass of Potassium Chloride 74.55g and figured out that the number of moles was 0.192.

Using elemental analysis to determine the percent mass composition of each element in a compound is the first step in creating an empirical formula. There are many different types of elemental analysis, but in this experiment gravitational analysis and Beer’s Law are used. Elemental analysis is first used to find the moles of each element, then converted to mass, and then the percent mass of the element in the product is found (2).

In a chemistry stockroom, a vial of an Unknown White Compound was found. In order to properly dispose of the substance, the substance has to be identified .The possible compounds has been limited to one of 15 different compounds. Also, approximately 5 grams of the Unknown White Compound (UWC) were available for testing. In order to determine the properties of the compound, a series of tests was conducted. These tests included a ph test, a conductivity test, a flame test, a sulfate test, a halide test, an ammonium test, a solubility test, and a carbonate test. Using the results of these experiments, it was hypothesized that the UWC is potassium chloride. To further confirm the hypothesis, a synthesis of potassium chloride was conducted.

Unknown white compound (823U) was discovered in the lab. In order to dispose of it correctly, the substance and its physical and chemical properties had to be identified. The unknown white compound was one of a list of 15 compounds. 5g of the unknown compound were given in order to correctly identify and discover its physical and chemical properties. In order to do so, a solubility test, a flame test, and ion tests were conducted. From the results of these initial tests and the given list of compounds, the unknown white compound was thought to be composed of sodium and a halide (I-, Br-, or Cl-). Of the list, NaCl was the appropriate compound, however NaC2H3O3 was also tested out of skepticism. To verify the identity of the substance, the solubility and flame tests were performed again along with a pH test. The pH tests of NaCl and NaC2H3O2 did not match that of the unknown white compound. The list of compounds had been entirely ruled out. The identity of the unknown white compound was revealed to be calcium chloride. To synthesize at least a gram (calculated to produce 1.2g) of CaCl2, the following reaction was completed.

Scientists use an instrument called a spectrometer to quantitatively determine the amount of light absorbed by a solution. The primary inner parts of a typical spectrometer are described below. The spectrometer has a light source that emits white light containing a vast mixture of different wavelengths of electromagnetic radiation. The wavelength of interest is then selected using a monochromator (“mono” meaning one and “chromate” meaning color) and an additional exit slit. The separation of white light into different colors (wavelengths) is known as diffraction. The selected light then reaches the sample and depending on how the light interacts with the chemical compound of interest, some of the light is absorbed and some passes straight through. By comparing the amount of light entering the sample (P0) with the amount of light reaching the detector (P), the spectrometer is able to tell how much light is absorbed by the sample.

A chemical equation demonstrates the quantity of atoms of every component that make up the compound. The atomic proportion of components in the compound is the same as the molar proportion of those components. This information can be applied to solve for the mass of one mole of a compound by including the molar masses of the constituent components.

They used different techniques such as microscopy, gas chromatography, and other technologies to identify the samples. Then after they collected their analyzes, they have to write

In this Crash Project, there will be two types of chemical equations being used in order to discover the following: The Murderer, The Murdered Victim, The compound that caused the crash, The passenger with the explosives, and the identity of the terrorist. The chemical equations is the Molecular Formula and the Empirical Formula. The Molecular Formula is a formula that identifies the amount of atoms present in a certain element in one molecule of a certain compound. On the other hand, the Empirical Formula is a formula that identifies the distribution of the elements present in a specific compound, rather than the actual amount of atoms in the compound.

Using the direct weighing and weighing by difference methods to find weight and mass of chemicals and compounds.

The best technology available today for studying the chemical composition of stars and planets is spectroscopy, a scientific tool that dissects light into its component colours (Astronomy mag. P.31). “A planet within 100 light-years of Earth is close enough to provide sufficient light for scientists to dissect light into its component colors” (Ray Villard, Astronomy ). Spectrographs are used by astronomers to observe discrete spectra. Discrete spectra are produced by gases, such as … when specific wavelengths of light are absorbed or emitted by the gases. This causes dark bands to appear on the spectrum where the specific wavelengths of light are absent. A scientist can

Emission spectra is referred to as the “fingerprint of the elements” because each element has a different pattern of emission or absorption lines that is detected in a spectrum.

Molecular spectroscopy is the study of absorption of light by molecules, it analyzes the molecular structure. Spectroscopy used absorption of light or radiation to indicate the structural properties of a compound. Molecular Spectroscopy interacts with radiation that is Ultraviolet, infrared and visible spectral regions. As shown in the electromagnetic spectrum in Figure 1, visible light is between 400-700 nm, the ultraviolet light is between 200-400 nm and the Infrared has a much higher wavelength than both.

With a yearlong project in my master degree, I studied enzyme (catalase) kinetics (by spectrophotometric analysis) in response to the activation/inactivation of MAP (mitogen-activated protein) kinase pathway of a plant pathogenic fungus (Botrytis cinerea). I am also familiar with different protein purification and characterisation methods including UV-VIS spectroscopy, SDS-PAGE, HPLC and mass-spectroscopy. I performed mass-spectroscopic analysis of isotopic composition of plant-leaf materials in one of my PhD experiment.

2. secondary ion mass spectrometry (SIMS) -A machine uses primary ions to push the ions in the object to the surface so they can be examined (Fraunhofer-Center Nanoelectronic Technologies)

What is mass spectrometry? According to the website premierbiosoft.com mass spectrometry is a capable scientific procedure used to evaluate known materials, to distinguish obscure mixes inside an example, and to illustrate the structure and substance properties of various molecules. The entire procedure includes the change of the example into vaporous particles, with or without fracture, which are then described by their mass to charge proportions (m/z) and relative abundances. This is basically a technique that study the effect of ionizing energy on molecules.