- Objectives:- Determine who else in the lab section has the same compound as yours- Methods to Achieve Objectives:- Melting Point Determination:1. Pack 2 melting point capillaries with your sample2. IMPORTANT to make sure the amount of sample in the melting point capillary be approximately 2-3 mm in height3. Use 1st of the melting point capillaries to determine an approximate melting point range of your compound.4. Use a high setting on the Mel-Temp apparatus that will give a heating rate of about 6-10 C/min5. After sample melts, turn off the Mel-Temp and use the diagram to estimate a setting on the Mel-Temp that will give a 1-2 C/min rise in temperature6. Use 2nd melting point capillary to determine the melting point of the sample (wait for the Mel-Temp to cool to at least 15 °C below the estimated m.p of your compound before you begin). 7. The lower end of the range is the temperature at which the first drop of liquid is seen and the upper end is the temperature at which the sample becomes a clear liquid. 8. Record any other behavior observed for the compound at its melting point. Some samples will decompose as indicated by darkening. Others may change color, bubble, sublime, or change in appearance at their melting points.- Solubility in Sodium Bicarbonate:1. Add a small amount (about the size of a BB or small pea) of your sample to 2 mL of 10% aqueous sodium bicarbonate. Mix well with a stirring rod and record your results. 2. Does it dissolve rapidly, slowly, or not at all? 3. After you have completed this test, dispose of the solution in the appropriate waste bottle in the hood.- Thin Layer Chromatography (TLC): – For comparison of Rf values1. Put approximately 6 mL of the developing solvent (a 50/50 mixture of ethyl acetate/hexanes) into the TLC chamber. 2. Mark the height of the liquid in the bottom with a faint pencil line about 10 mm (1 cm or approximately 0.5" from the bottom of the plate. 3. Use the line to measure the distance the compounds move from this point). The line shouldbe above the solvent level in the jar when the TLC plate is placed inside. 4. Make a short faint vertical line crossing the first line to indicate the point where you will spot your compound.5. Dissolve a small quantity of your sample (about the size of a BB or a small pea) in about 4 mL of 95% ethanol. 6. Take the TLC spotting capillary tube and practice your spotting technique using this solution and a paper towel (you need to spot less than 5 μL of this solution so you have plenty to practice with). 7. Make as small a spot as possible—1 to 2 mm in diameter or less (less than 1/8"). 8. Do not let all of the material that is pulled up by the capillary tube to drain on the plate (or towel) in one application. Gently dotting the tube onto the plate.9. Check to see that you have enough compound on the plate by looking at it with the UV lightafter the solvent has evaporated from your application—if spot is clear, there’s enough material to run a successful TLC plate.10. After you’ve spotted your plate, let the spot dry, then place the plate into your TLC chamber, place the lid on the TLC chamber and allow its contents to sit until the solvent has risen almost to the top of the plate. 11. When the solvent is within 10 mm or less of the top of the plate, remove the plate from the chamber and quickly draw a line to indicate where the solvent front was12. Measure with a ruler the distance the solvent front traveled from the origin (the first line) and also measure the distance that your compound migrated from the origin.13. Now determine the Rf of your compound. Like the melting point, the Rf of a compound in a specific solvent system is highly reproducible.- Mixture Melting Point Determination (m.m.p):1. Using the m.p you obtained, the solubility data, and the ~of your unknown, locate someone in the lab who you think has this same material as their unknown. 2. Make an intimate mixture by grinding a small amount of your unknown and an approximate equal amount of their sample on a clean watch glass. 3. Determine the melting point of this mixture. This is a mixture melting point.4. If the m.p of the mixture is lower and the range is broader, you have made a mixture of two different compounds and have not found a match for your unknown. If the melting point range remains narrow and is not depressed, it is likely that the two materials are the same.5. Then obtain m.m.p of your sample and some of the labeled standards (for the mixture, choose standards with melting points closest to your experimental m.p) to identify the structure of your compound.6. Take a small amount of your unknown (about the size of a BB or smaller). Thoroughly mix this with an approximately equal amount of the standard of the material you think you might have. 7. If the m.m.p is the same as the m.p observed for each of the two pure compounds (unknown and standard), then the two compounds should be identical. 8. Check with T.A to determine the accuracy of your identification.- Mixture Melting Point with Inorganic Solid:1. Locate the sample vial labeled “Organic/Inorganic Mixture.” 2. Record the names of the components of this vial and the m.p of the pure organic material as listed on the vial. 3. Load some of this mixture to a m.p capillary and determine the temp range and observe material in the capillary melting.4. Don’t heat the sample more than 10 °C above the melting point of the pure organic compound.5. Record your observations of the mixture at this point.- Reagents and Solvents:Resorcinal Acetanilide Benzoic Acid Benzamide Maleic Acid Urea CholesterolSalicyclic Acid Ethyl acetate/HexaneSilica GelAluminaEthanol- Properties (MW, mp, bp, density, etc.):Melting point (m.p)Mixture Melting Point (m.m.p)Rf - Safety:Hot glass looks like cold glass. DO NOT hold the tube while tapping it on the surfaceDO NOT add or return any material to any of the sample vials!YOU MUST USE GOGGLESWash your hands after handling the plate from the TLC, the material can scratch and ulcerate the corneas of your eyesStaring directly into the low-powered light for extended periods can cause eye damage when preforming the TLCDo not wash the jar used in TLC with water or acetone - List Apparatus and Equipment used:Mel-Temp Apparatus Capillary TubeJar (TLC chamber) Low-power LampStirring RodElectronic Thermometer w/ thermocouple wire