In order to ensure the most accurate data, a purification was performed by the process of recrystallization. To perform the recrystallization the powder was dissolved in a minimal amount of hot ethanol/H2O solvent that allowed the unknown powder to crystallize properly when cooled. This process allowed for the removal of soluble impurities when suction filtered. A sample of the unknown acid was weighed at 8.24 g, and it was found that 164ml of a 40% ethanol, 60% H20 solvent dissolved the 8.24 g of unknown acid when heated. The beaker containing the dissolved acid was then placed in a beaker containing ice, allowing the unknown acid to recrystallized. After vacuum filtration, the recovered unknown was dried and weighed at 6.92 g. The percent recovery was determined by the following calculation: (8.24--6.92)8.24 x 100% = 16% loss = 84% recovery of unknown.
The melting point of the unknown was determined for both pure (recrystallized) and impure (original) powders. To perform thee melting point procedure the powders were placed in small tubule. The tubule was placed in a Mel-temp device and the melting range was recorded. The data is present in the form of a range in the following chart:
Substance Starting point (°c) Ending Point (°c)
Pure Acid (recrystallized)
Pure Acid 2nd Range 125.3
- 7 129.2
Impure Acid (original) 124.1 128.2
In order in determine the equivalent weight of the unknown acid, a base was needed at a known or "stan...
... middle of paper ...
...erivative of the unknown acid, it was determined that the unknown acid 94 is sebacic acid [HOOC(CH2)8COOH] whose structure is shown below.
A comparison of the experimental value for the melting point of the melting point of sebacic acid yields an error of 5%, represented by the following calculation: (133°C-125°C)/133°C x 100% = 5%. A comparison of the experimental value for the equivalent weight of sebacic acid yields an error of 2.5%, determined by the following calculation: (101-98)/101x100% = 2.5%. A comparison of the experimental value for the melting point of the amide derivative of sebacic acid yields an error of 0%. This was determined by the following calculation (168-168)/168x100%=0. On average, the error inherent to the total project was 2.5%. In the future, it would be desirable to further support the identification of the unknown
Need Writing Help?
Get feedback on grammar, clarity, concision and logic instantly.Check your paper »
- The goal of the project was to characterize an "unknown" organic acid in order to make a proper identification of the acid, while learning proper techniques for scientific measurement and analysis of error. In order to ensure the most accurate data, a purification was performed by the process of recrystallization. To perform the recrystallization the powder was dissolved in a minimal amount of hot ethanol/H2O solvent that allowed the unknown powder to crystallize properly when cooled. This process allowed for the removal of soluble impurities when suction filtered.... [tags: Chemistry]
912 words (2.6 pages)
Exploring Factors That Affect the Rate of a Chemical Reaction Involving Magnesium and Hydrochloric Acid
- What factors affect the rate of this chemical reaction: Magnesium + Hydrochloric Acid Magnesium Chloride + Hydrogen Mg (s) + 2HCl (aq) MgCl2 (aq) + H2 (g) Prediction I think that my results will show that the hydrochloric acid with a molarity of 2 will finish reacting the quickest because it is the strongest hydrochloric acid and I predict that the slowest experiment to finish reacting will be the 0.4 molar strength of hydrochloric acid. I think that the results will go slower and slower the nearer they are to the 0.4 strength of hydrochloric acid.... [tags: chemistry, chemistry experiment, lab report]
1528 words (4.4 pages)
- Investigating the Factors Affecting How Quickly Hot Water Cools Aim: -to sees how quickly water-cools after boiling at different volumes of water with lids on. Background: - heat can be lost in many ways and also gain. In human we gain heat by chemical reactions happening mostly in contracting cells of active muscle and the cells of the liver. We also gain it from the sun, which is absorbed through the skin and by eating hot food and drinks. Heat is lost to the air by exposed surfaces of the body by conduction convection and radiation.... [tags: Chemistry Lab Report]
972 words (2.8 pages)
- Lab Report The Preparation of Organic Compounds Aspirins and Oil of Wintergreen Introduction The purpose of this experiment is to prepare two organic compounds (aspirin and oil of wintergreen) and to illustrate the typical organic reactions. Students will also learn some techniques commonly used in organic synthesis and the meaning of the terms theoretical yield, actual yield, and percent yield. Both Aspirin (acetylsalicylic acid) and oil of wintergreen (methyl salicylate) are commonly used organic compounds.... [tags: Science Experiment, Chemistry]
327 words (0.9 pages)
- Lab Report Testing the Hardness of Water Water is the most important molecule that exists on the Earth. Without water living beings would not be able to live. Water is used for an immeasurable number of things. There are many properties of water, which makes this molecule so unique. One which people overlook is hardness. Hardness is defined in the Chemistry: The Central Science by Prentice Hall's as being "water that contains a relatively high concentration of Ca2+, Mg2+, and other divalent cations." Water containing these ions is not a health hazard; however, it is a problem for industries and households.... [tags: Papers]
1629 words (4.7 pages)
- Lab Report Determining the Molar Volume of a Gas Introduction: This lab was designed so that we, the students, could learn how to determine the molar volume of a gas effectively. Method: The first step that we took to accomplish our goal was to put on our safety goggles and choose a lab station to work at. We received one 400ml beaker, one polyethylene pipet, two test tubes with hole rubber stoppers, two small pieces of magnesium (Mg), one thermometer and a vial of hydrochloric acid (HCl). We took the 400ml beaker and filled it about 2/3 full of water (H20) that was 18 OC.... [tags: Papers]
333 words (1 pages)
- Investigating the Solubility of Table Salt in Distilled Water at Different Temperatures The aim of this essay is to explain and discuss the drug cannabis and its effects in relation to biochemical, behavioural and psychological factors. The introduction will outline a brief history relating to the drug and include both the medicinal and recreational purposes of its use. The main discussion will explain how the drug chemistry affects the nervous system emphasising what neurotransmitter is effected and also what behavioural and psychological implications this has on the user.... [tags: Lab Report]
2162 words (6.2 pages)
- There are many ways to examine the subject of alchemy, including alchemy as a source of symbolism, psychology, and mysticism. It has also been an influence on the world view of various writers, artist, and musicians. The focus of this report is alchemy as a pre-chemistry, which gave a new impulse towards the preparation of medicinal remedies and also was a major influence on today's scientific investigations.Alchemy is an ancient art, practiced in the Middle Ages. The fundamental concept of alchemy stemmed from Aristotle's doctrine that all things tend to reach perfection.... [tags: essays research papers]
659 words (1.9 pages)
- Introduction During lab on Monday, April 9, 2002 our class conducted a lab on water chemistry and pollution. The two bodies of water that were choose as samples where, the Wall pond and the HGTC pond. Each group had to test the water for Temperature, Dissolved Oxygen, Nitrate, Phosphate, pH, and Turbidity. Only two people where chosen to test the waters for Coliform bacteria. “Coliform bacteria are not pathogenic (disease causing) organisms, and are only mildly infectious. For this reason these bacteria are relatively safe to work with in the laboratory”.... [tags: Water Quality Lab Report]
1275 words (3.6 pages)
- A. Question Being Addressed: The purpose of this research is to determine the relationship between pollution and water while the physical properties of water are held fixed. I am going to compare the “polluted” water with the purified water and see if it changed in anyway. For this experiment, I’m going to use water containing sand and oil to get “polluted” water. Also, I am going to use two methods of separation of substances, distillation to remove the oil, and filtration to remove the sand. Then I am going to use activated charcoal to remove any dissolved substances in the water.... [tags: essays research papers]
478 words (1.4 pages)