S&f of melting point apparatus& colorimeter PDF

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melting point apparatus& colorimeter...

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Melting Point Apparatus A Melting Point Apparatus is recognized as a Scientific Instrument which operates by allowing Chemists specifically to find out the identity of a sample of a compound that depends on the temperature it turns from a solid into a liquid and to also pinpoint its purity. It is tested by using a Capillary Tube as well as a small grain of the sample which would be tested. Once the small amount of the sample is inside the capillary tube, it is set inside the hole of the apparatus and observed in the observation window. Also, depending on the temperature the voltage control is set on, the temperature starts to increase while the sample begins to liquidize.

Thermometer: A Thermometer is described as a long glass stem with a silver bulb at the end of the tool. For the Melting Point Apparatus, it has the function to measure temperature with higher levels of accuracy. It can measure temperature in solids, liquids or gases. The silver color in the Thermometer conveys that it contains Mercury. As the temperature increases when testing the samples, the Mercury part of the Thermometer expands as once the temperature decreases, the Mercury contracts and lowers the reading of the temperature. Melting Point Capillary Tube: A Melting Point Capillary Tube is small thin glass test tube. It has a similar function as a Glass Test Tube which is to gently hold, heat as well as mix small amounts of liquids or solid type chemicals in the process of experiments. The Glass Tube contains Boron and Silica which resists temperature change and prevents the glass from reacting with the chemical. However, the similarity of a finger like Glass Tube and a Melting point capillary tube is that it is much smaller and tests very tiny granolas of any solid. The Melting point capillary tube is placed into the hole of the apparatus to easily monitor and observe the sample. The Melting point tube is utilized by placing a watch glass and the solid sample which would be used to heat up in the apparatus. You carefully tilt the tube as the open end is facing the watch glass and

you add the compound into the tube. Too much of the solid could block the opening which means you would have to use a coin or a pin for it to go all the way in. Observation Window: The Observation Window in the Melting Point Apparatus is a round glass clear window. It has the function to observe what occurs within the machine as well as finding a precise melting range of the sample. Light Source: The LED Light Source in the Melting Point Apparatus however is located within the machine which has the function to illuminate the inside of the machine with a magnified lens to be able to give a clear as well as a broad view of the samples which contains the unknown solids. Voltage Control knob: The Voltage Control is originally a device which is able to maintain voltage from any power source which is the Melting Point Apparatus. The Voltage Control knob in the apparatus has the function in providing the temperature for the capillary tube. This indicates that it can turn on and can be achieved at any temperature. Fuse: A Fuse is a safety device which contains a piece of wire that can easily melt. Once the current goes through the wire, it heats up which then melts and breaks. Line Chord: A Line Chord is a cable type that can temporarily connect the appliance to the Mains Electricity supply and to either a wall socket or an extension cord. On/Off Switch: The On/Off Switch is built in at the center of the Melting Point Apparatus, this has the function to launch the machine to keep it running smoothly. The determination of the Melting Point Apparatus in a compound is to test whether the sample is pure or impure. The machine can be able to identify the compound based on the temperature and whether it turns from a solid to a liquid. The substance which contains soluble impurities melts within a low temperature than a pure compound as well as melting over varied temperatures. This means that the smaller the range the higher the purity of the sample. References: https://sites.google.com/a/asu.edu/chemistry-biochem-technology/melting-point-apparatus https://www.quizover.com/course/section/advantages- of-melting-point-analysis-by-openstax https://www.reference.com/science/laboratory-thermometer-23ef1b6cafd2bb8a https://en.wikipedia.org/wiki/Power_cord https://www.reference.com/science/test-tubes-used-572165e257d03bd8 http://bohr.winthrop.edu/faculty/grattan/link_to_webpages/courses/chem304/Melting%20Point%20Instru ctions.pdf http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa_pre_2011/electricity/mainselectrev3.shtml

Colorimeter A Colorimeter is a Scientific Instrument used in Colorimetry. It is a sensitive light device which can be used to measure the absorbance in a particular wavelength of light by passing through a liquid sample. This device is able to measure the concentration of the color which develops on introducing a specific reagent into a solution. The Colorimeter is able to identify and determine color which can be based on red, blue and green components once the light is absorbed by the sample. Once light passes through the medium, part of the light is being absorbed indicating that it decreases the amount of light transmitted. Overall, this device works by the law of Beer-Lambert which is stated that once the absorption of the light is transmitted through a medium, it means that it is directly proportional to its concentration of the medium. The Colorimeter consists of two types which are Color Densitometers that has the function in measuring the density of primary colors as well as the function of a Photometer is that it measures the reflection of color and transmission of color. The three main components of a Colorimeter is the Light Source, a Cuvette and a Photocell. Also, equipment such as colored filters or particular LED lights to be able to generate color. But the output from the Colorimeter can be viewed by an analog or a digital meter depending on the absorbance or transmittance. Besides a Colorimeter could consist of a Voltage Regulator which has the function to protect the instrument from variations within a mains voltage.

Cuvette: A Cuvette has the structure of a small tube of a square cross section sealed at one end of the vessel. It has the function to hold samples in a process of a spectroscopic analysis. These Cuvettes can easily absorb light once placed within the Colorimeter. Light Source: A Light Source is an LED Filament Bulb which is built in the Colorimeter. Photocell: A Photocell within the Colorimeter has the function to detect the light that is passing through the sample solution. The working principle of the Colorimeter is that a ray of light with a certain wavelengths is being passed through a solution and measuring the light which passes through on the other side. The more concentrated the solution is it conveys that more light will be absorbed which can be identified in the difference between the light at its origin and also after it passes through the solution. In order to dictate the concentration of an unknown sample, several sample solutions of a concentration (e.g: Copper Sulfate) solution) is tested. Once the process is complete, the results shown is plotted onto a graph with the Concentrations on the Y axis and the Absorbance on the X Axis. This forms a calibration curve. Nonetheless, to be able to measure concentration, results from the unknown sample is compared to the known sample. (Copper Sulfate)

In the matter of the application of the Colorimeter, it can be used in a wide setting and industries. They can be widely used to monitor growth of a bacteria or yeast culture as they provide a high accurate and reliable result when it is used to assess the color in bird plumage. In the printing industry, Colorimeters are basic elements in color management systems. Also, small portable devices can analyze the brightness and color contrast on a Television or a Computer screen. This can allow them to adjust the settings to provide the best quality picture that suits the user.

References: https://en.wikipedia.org/wiki/Colorimeter_(chemistry) https://www.reference.com/science/relationship-between-absorbance-concentration-2f98d821d965a963 http://www.azosensors.com/article.aspx?ArticleID=324...