Trigonometry

Melting Point Data Table Compound Aspirin Caffeine Salicylamide Actual MP (ºC) 93 - 98 260 - 262 96 - 102 Expected MP (ºC) 135 236 140 Percent Error (%) ~30% ~12% ~30%

When the product was completely dry two different melting points were recorded, averaged and then compared to the standards in order to identify the product. The theoretical yield and percent yield were also calculated.

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.

4- chlorobenzoic acid which was the aqueous layer has a theoretical melting point of 240-243°C, the organic layer, 4-chlorobenzyl alcohol has a theoretical melting point of 68-71°C. During our experiment we were unable to collect any data for the organic

Discussion: As seen in the melting point determination, the average melting point range of the product was 172.2-185.3ºC. The melting points of the possible products are listed as 101ºC for o-methoxybenzoic acid, 110ºC for m- methoxybenzoic acid, and 185ºC for p- methoxybenzoic acid. As the melting point of the sample

The melting point was determined for both the crude and purified aspirin samples. The crude aspirin sample produced a melting range of 90˚-101˚celsius and the purified aspirin sample produced a melting of 117˚-132˚celsius. The melting point of the crude sample was determined to be 101˚C and the melting point of the purified sample was determined to be 132˚C. The

Organic chemists use melting points to identify compounds and determine its purity. Two temperatures that need to be noted are the point at which the first drop of liquid appears from the substance and the point at which the entire mass of the solid substance turns to liquid. The range between these two points is the melting point. The melting point is used to determine the purity of a substance because if the substance is pure then its melting point will be higher. Also, if the substance is pure then its melting point will be narrower. The melting point will be lower if the substance is impure. Melting point can be used to identify an unknown compound by mixing it with a known substance with a known melting point. If it is the correct material

The percent yield of the crude product from experiment seven was 77.6%. The melting point of the crude product was 100 ° C – 119.2 ° C. The melting point range was 19.2 ° C. The percent yield of the pure product from experiment seven was 63.2%. The melting point was 100° C – 108.2 °C. The melting point range was 8.2 ° C. The percent yield of benzilic acid from experiment 8 was 66.9%. The melting point was 139.9° C – 143.3 °C. The melting point range was 3.4 °C. According to PubChem, the melting point of benzilic acid is 150 °C. The reason why the experimental melting point of benzilic acid is lower than the literature value is because there might have been some impurities in the benzilic acid. The reason why there might have been impurities in the benzilic acid is because the crystals might not have been rinsed off with enough water or they were not dried under the vacuum long

Introduction: The experiment's goal was to determine the freezing point of a pure solvent and the freezing point depressions of two solutions. The freezing point and the freezing point depressions were determined by graphing the temperature of the pure solvent and two solutions as they cooled and observing when crystals first formed.

A pure organic compound melts or freezes fairly sharply over a specific temperature range called its melting point. This physical constant can help identify a substance. Generally, any impurity added to a pure substance will lower its observed melting point and increase the range over which melting occurs. Therefore, when two pure organic substances possess a similar melting point, a mixture containing both substances will often melt at a lower temperature and over a broader range. Conversely, if a mixture of a known and unknown substance actually contains a single substance, the melting point of the mixture will not deviate from the melting point of the known.

Experimental Section: The first known substance we used was Biphenyl. 68 degrees Celsius is the known melting point. We used the capillary method and observed the melting point using a Mel-temp device. The next substance whose melting point we observed was 90 % Naphthalene, 10 % Biphenyl. In the last part of the experiment I observed the

The sample metals are put to boil. In the first trial, the investigators use sample metal #2. Pour an amount of distilled water in the beaker and measure. After obtaining the

This would indicate that during the recrystallization there was a reduction in the percentage yield of the production. The obtained final product melting point rang was 76.2-780C. This would show that the experimental melting point was very close to the literature value of 78 - 80°C

The experiment conducted was designed to discover what solutes allow for ice to melt at a faster rate.

In order to classify and identify materials of a wide variety, scientists use numbers called physical constants (e.g. density, melting point, boiling point, index of refraction) which are characteristic of the material in question. These constants do not vary with the amount or shape of the material, and are therefore useful in positively identifying unknown materials. Standard reference works have been complied containing lists of data for a wide variety of substances. The chemist makes use of this in determining the identity of an unknown substance, by measuring the appropriate physical constants in the laboratory, consulting the scientific literature, and then comparing the measured physical constants with the values for known materials. This experiment illustrates several approaches to the measurement of the density of liquids and solids.