Unit 9 Final Lab Report

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.

To understand what color is, we first need to understand what light is. Light, as perceived by humans, is simply electromagnetic radiation with wavelengths between roughly 380 nm and 740 nm. Wavelengths below 380 nm and above 740 nm cannot be seem by the human eye. Electromagnetic radiation with a wavelength just below 380 nm is known as ultraviolet radiation. Electromagnetic radiation with a wavelength just above 740 nm is known as infrared radiation. The sun, black lights and fluorescent lamps are all sources of ultraviolet light. Heat is a source of infrared radiation, which is how thermal vision works.

1- Different elements give off different colors when heated because electrons go farther the nucleus, or to an upper energy level, and once they go back to their original orbit (energy level), they release colors because of the amount of energy released. This also happens because different elements are in different orbits and they hit different orbits as well.

The mean voltage of the battery terminals while connected to the identification resistors is presented in Figure ‎4 12. These samples have been pulled out from the voltage sensor of the PEB panel. The voltage decreased as expected from 12.53 to 12.5 during first 20 seconds of connection to the

Spectrophotometry is a routine laboratory test that has the added advantage of being able to

This was supported by the data collected during the exercise; Neon had multiple lines within every color in the visible spectrum, whereas the other elements generally did not or had fewer than Neon. The emission spectrum for every element was different because every element has a series of shells that are approximately in the same place; when it is heated, the electron moves from a higher orbital to a lower orbital and releases a quanta of energy. When this happens, the emission spectra for each element is produced. Since the number of protons and electrons are different, the quanta required are different and produce a different wavelength. In future experiments, it would be interesting to perform flame tests on different compounds, and see what color the different elements chemically combined with each other

He split the light of flames into its own wavelengths, by using a prism and discovered that every element emits a different mix of wavelengths that can be used as a identifier, just like fingerprints.

Light is made up of different wavelengths (visible light is made up of the rainbow). If a substance could absorb specific wavelengths of light, then each substance will have a unique ‘fingerprint’. This could be proven by forcing light through a substance and seeing the different wavelengths of light that were displayed on the other side. If there are dark lines, that means that wavelength was missing and was absorbed. A second way to prove this would be to test if that same substance would release the wavelength it absorbed. In the candle experiment, the salt should give off a wavelength because of the intensity of the flame. If it is the same as the sodium street lamp, then that proves sodium will absorb and emit a specific wavelength consistently.

They obtained 0.5g from each vial and used a LECO analyser to perform high temperature combustion; they analysed the total carbon and nitrogen in each sample. Another 0.5g sample was digested with nitric acid and analysed for phosphorous, calcium, potassium, magnesium, sodium, sulfur, aluminum, boron, cupper, iron and zinc using Inductively Coupled Plasma Optical Emission Spectrometry (ICPOES). This method relies on the fact that, when excited, elements emit electromagnetic radiations at characteristic

Astronomers can use the light given off by stars for many things. With the light given off by stars they can see the distance that the star is located from earth. They can also use the light given off by stars to see what that star is composed of. When something is burnt to the point that it glows, for example stars, it shows features that can help you decide what the star is made up of. This is because unique chemicals give off its own unique spectrum of light when they are burnt to the point that they glow. Each product gives off a different spectrum, this can be compared to be almost like a fingerprint. Cool gases will also absorb various wavelengths of light and produce a spectrum that has dark lines at different places. With this in effect,

In the AAS the sample under investigation is atomized and mixed with fuel-gas air mixture and introduced into the burner at a controlled rate. In the flame the solvent is evaporated and the sample is disassociated into atoms. The flame only acts as a trough of atoms of the elements under investigation. A beam of resonance radiation is provided by the hollow cathode lamp of the element under investigation is allowed to pass through the flame and then spectrophotometer assembly where in the transported light from the sample is measured by the photomultiplier, amplifier and recorded in convenient scale. In graphite AAS the technique is similar to flame atomization except that the flame is replaced by an electrically heated closed graphite tube

There are many possible electron transitions for each atom, and each transition has a specific energy difference. This collection of different transitions, leading to different radiated wavelengths, make up an ‘emission spectrum.’ Each element's emission spectrum is unique. Therefore, spectroscopy can be used to identify the elements in matter of unknown composition. Thus, spectroscopy is an important tool in

When elements are heated they emit light at certain wavelengths which we perceive as colors. Spectroscopy analyzes all the wavelengths in a particular beam of light and this information can be used to determine what elements the source of the light contains. So with any object that emits light, we can determine what

The way that metal ions react when exposed to heat is the principle behind color production. Each metal ion produces a specific color (see table). The color is produced when the electrons in the metal ions are "excited", causing them to jump to a different energy shell. It is when the electrons return to "ground state" that they emit their own light.

Fire, from humans’ first interactions with it, has been terrifying, delighting, and mysterious all at once. Yet it is impossible to imagine a day passing without any interactions with the phenomenon. From burning wood in the fireplace, to preparing tea on a stove operating with natural gas, to using charcoal for a backyard barbecue, different objects are chosen as the source of combustion depending on the task that they need to accomplish. Furthermore, with parents, teachers, and firefighters incessantly warning students not to place certain substances close to nearby ignition sources, one cannot help but wonder how the chemical characteristics of these substances play a role in determining