Pure Urea And Cinnamic Acid

Procedure: 1. The physical properties of the solids were observed. 2. The hardness of the solids were tested using mortar and pestle. 3. The conductivity of the solids were tested using electrical apparatus. 4. The melting points of the solids were tested by placing them in crucibles and heating them using a hot plate.

Other substances that dissolve in water also lower the freezing point of the solution. The amount by which the freezing point is lowered depends only on the number of molecules dissolved, not on their chemical nature. This is an example of a colligative property. In this project, you'll investigate different substances to see how they affect the rate at which ice cubes melt. You'll test substances that dissolve in water (i.e., soluble substances), like salt and sugar, as well as substances that don't dissolve in water (i.e., insoluble substances), like sand and pepper. Which substances will speed up the melting of the ice?

97 g1.07 g ×100%=90.7% Drawing of TLC Discussion Melting points are indicative of identifying an unknown product and the level of impurity the product contains. In this case, the possible identity of the product based on its melting points are determined by comparing the obtained melting points of the product to the melting points of the five possible products. Two mini capillaries, containing the product only, were used to determine the product’s melting point. For one mini capillary, the temperature range was 132.1-134.2℃, and the product’s melting point for the second minicapillary ranged from 135.1-137.5℃. In addition, melting points were obtained with the product mixed with meso-hydrobenzoin. The temperature range was 135.0-136.0℃ and 135.0-137.5℃. Although the recorded melting point values fall into the racemic range, but the results still indicate that the product is a meso-hydrobenzoin. The melting point values for the product mixed with the meso-hydrobenzoin standard explains that it is unlikely that the product is racemic. The melting point values were two degrees from each other due to the meso-hydrobenzoin standard making

The beaker was slowly heated on a hot plate with low stirring until most of the stilbene was dissolved. 0.4 g of pyridinium tribromide was measured and added to the beaker after 5 minutes of heating. Small amounts of ethanol were used to clean the sides of the beaker. The beaker was heated for an additional 10 minutes on low temperature. An ice bath was prepared. The beaker was removed from the hot plate and left to cool to room temperature. Once at room temperature, the beaker was placed in the ice bath for 15 minutes. The solid product was collected through vacuum filtration and the product was weighed and a melting point was taken. Waste was disposed of in the correct waste bins and lab bench was cleaned

3. Maleic acid has a melting point of C and Fumaric acid has a melting point of C. The substance that has a higher melting

In determining the melting point range of the aspirin, a capillary tube (sealed at one end) was one-third-filled with the dried aspirin. The capillary tube and a thermometer were immersed in an oil bath. The temperature at which the solid started to melt and the temperature when the entire sample was completely liquefied were recorded as the melting point temperature range.

After each of the solids were completely dry, each was placed into a MelTemp device. The temperature at which each solid began to melt and completed melting was recorded.

Percent Yield = (1.03 g / 1.223 g) x 100 = 84.2% Melting Point Range ( ̊C): 83.9, 84.4, 85.0 Melting Point Average ( ̊C): 84.43 Rf Values Starting material = 4.0/5.5 = 0.73 Final product = While we refluxed the solution there was no color change, the solution stayed clear. After gravity filtration the solution stayed clear. After roto vap, solution was a milky brown color.

In the middle of the experiment, the two solutions created an odor. During the second half of the trials, the temperature began dropping back to its original temperature, 24oC.

The amount of tablets did effect the temperature of the water. Our findings made our hypothesis incorrect. The temperature of the water did increase as the number of the tablets increased also. In this experiment, the finding were quite surprising, simply because I thought that the temperature of the water

Attractions between water and other molecules, which is adhesion, is also possible because of the polarity as well. In relation to hydrogen bonds, water’s high specific heat is changed when hydrogen bonds are made or broken. When a hydrogen bond breaks, heat is absorbed whereas when a hydrogen bond forms, heat is released. In addition to HSH, ice is able to float in liquid water because hydrogen bonds in ice is more structured than in water, making the ice less dense. Also, water is a versatile solvent because of its polarity, which helps it form hydrogen bonds (mentioned above). The structure of water molecules also affects the dissociation of water, where H2O breaks into H+ and OH- due to the polarity of the

Procedure: This lab starts off by making sure the logger pro and temperature probe are in proper condition. Then, the data collection must be adjusted to 15 minutes and 12 samples/ min. After that a Bunsen burner must be set up by assembling a ring-stand, ring, and wire gauze, and a crack-less beaker is used to boil some water. First the beaker and the large watch glass need to be weighed and the mass has to be recorded using a triple beam balance. Next, the beaker with 200g of ice is placed on the ring stand, and immediately heated over medium flame. An important note is to make sure the flame is perfectly adjusted so the ice does not melt on the counter while trying to adjust the flame. Furthermore, place the temperature probe in the ice so it is not resting at the bottom of the beaker, it is best to secure it with a small clamp. Additionally, click the green start button on the computer and stir continuously with a glass rod until the ice is completely melted. Once the ice has melted which is somewhere between 3-5 minutes, the stirring rate will slow

In the first part of the experiment trans-cinnamic acid began to melt rapidly at 133 °C and had completely liquefied at 135.9 °C. Urea began to melt rapidly at 133 °C, just as the trans-cinnamic acid, but had completely liquefied at 134.7 °C. Both urea and trans-cinnamic acid had true

‎ The volume is definite if the temperature and pressure are constant. When a solid is heated above its melting point, it becomes liquid, given that the pressure is higher than the triple point of the substance. Intermolecular (or interatomic or interionic) forces are still important, but the molecules have enough energy to move relative to each other and the structure is mobile. This means that the shape of a liquid is not definite but is determined by its container. The volume is usually greater than that of the corresponding solid, the most well known exception being water, H2O. The highest temperature at which a given liquid can exist is its critical temperature.[5]

Melting Points Elizabeth McGrail Organic Chemistry I 25 January 2013 ABSTRACT The objectives of this lab are, as follows; to understand what occurs at the molecular level when a substance melts; to understand the primary purpose of melting point data; to demonstrate the technique for obtaining the melting point of an organic substance; and to explain the effect of impurities on the melting point of a substance. Through the experimentation of three substances, tetracosane, 1-tetradecanol and a mixture of the two, observations can be made in reference to melting point concerning polarity, molecular weight and purity of the substance. When comparing the two substances, it is evident that heavy molecule weight of tetracosane allowed