Three sources of error that may have occurred during this lab include Essay

Submitted By gugu5
Words: 614
Pages: 3
Open Document
MELTING POINT DETERMINANTION
Aradhna Sharma
Sidra Choudhry

Dr. O’Sullivan
May 12, 2015

Aradhna Sharma May 12, 2015
Melting Points of Organic Compounds
In this lab, it was observed that pure compounds have a sharp, narrow melting range, while impurities caused the melting point range to become relatively lower and broader. The unknown sample was identified as trans-cinnamic acid. The true melting point range of the unknown compound was 132.5- 135°C which is extremely close to the experimental melting point range for trans-cinnamic acid, which was 133-135°C. The mixed melting points of the unknown sample and the other three known compounds, urea, ASA and benzamide, were low and broad. This is evident as the melting point ranges are significantly lower (approximately 6 degrees Celsius) less than the true melting points of both the unknown and known compounds in each of these cases. However, the true and mixed melting point for the trans-cinnamic acid and the unknown compound are extremely similar which indicates that they are the same compound. Also, the mixed melting point range is sharp, with a range of 2°C, which indicates a pure organic compound. The literature value of trans-cinnamic acid is 134°C, which falls within the experimental melting point range.
The mixed melting range for the unknown sample and trans-cinnamic acid was sharp, narrow and was almost identical melting point range as the unknown compound and trans-cinnamic acid. This allowed for the identification of the unknown sample as trans-cinnamic acid. Also, the literature melting points for benzamide, urea, ASA and trans-cinnamic acid fell within the experimental melting point range for each compound, so these samples were eliminated as possible outcomes for the unknown compound. The literature melting point of 132.4°C for urea fell within the experimental melting point range of 131-133°C. The literature melting point of 136°C for ASA was in accordance with the higher end of the experimental melting point range of 134-136°C. The literature melting point of 134°C for trans-cinnamic acid fell within the experimental melting point range of 133-135°C. The literature melting point for benzamide of 128°C in accordance with the lower end of the experimental melting point range.
The slight error of 0.5 °C (or 25% error) that occurred between the difference in the melting point range of the unknown sample and trans-cinnamic acid, indicated the presence of impurities and/or human
Show More

Related Documents: Three sources of error that may have occurred during this lab include Essay

Ethyl Ethanoate Lab

by the reaction between an organic acid (acetic acid) and an alcohol (ethanol). This ester is probably the most commonly known and used. Ethyl acetate’s uses include being an artificial flavor or smell, being a solvent in procedures such as decaffeinating tea, and it is also used in nail polish removers and cigarettes. In this lab, ethyl acetate is formed by a process called distillation. The theoretical yield for this experiment is 15 g of ethyl acetate. To come up with the theoretical yield, I found…

Words 1449 - Pages 6

Essay on Peroxidase

In a 1-2 page report, address the following. The first part of your report is the Results section of a scientific paper. In this section, present the results of your experiment without any interpretation. Be sure to adequately answer the following questions: How did the rate of the reaction change as you changed each of the three variables? If you vary the temperature, after a certain temperature, the enzymes will become denatured and then the rate will decrease. Each enzyme functions at…

Words 1468 - Pages 6

pigment and photosynthesis Essay

Problem: What question(s) are you trying to answer? Include any preliminary observations or background information about the subject If we use paper chromatography to separate the pigments in spinach leaves, then we will see several different pigments because plants use other pigments besides chlorophyll a (the green pigment) to capture visible light for photosynthesis. 1. What factors are involved in the separation of the pigments? a. Some factors that may be involved in the separation of the pigments…

Words 1037 - Pages 5

Osmosis: Experiment and Lab Essay examples

laboratory. The laboratory will count as one of two grades for this course. It is important to learn proper laboratory technique and the correct way of reporting your results. Formal Lab Reports: You should keep ALL COMPLETE copies of lab reports in your 3-ring binder in a back section/tab labeled “AP Lab Reports”. Ultimately, all formal labs and lab worksheets should go into this binder for later use during review. Formal lab reports will be done on the computer and NEED TO BE TYPED and submitted…

Words 5942 - Pages 24

Medication Errors In Health Care

Medication Errors This eye-opening statistic for the prevalence of medication errors displays the negative outcome of avoidable mistakes in the health-care profession: “researchers estimated that potentially preventable adverse drug events kill 7,000 Americans annually and that medication errors that result in harm are the number-one cause of inpatient fatalities” (Anderson, 2010). Medication errors are preventable mistakes that are frequent in health-care settings, therefor striving to improve this issue…

Words 1791 - Pages 8

biology prac reports Essays

Practicals prescribed in this document Each report should cover the headings, as far as possible, shown in the Lab Report Template; Due Date: Practical reports should be submitted in the week following the practical and must be maintained in a folder to be submitted on Monday 29th June 2014, week 9 of Term 2. Lab Report Template Title: a brief, concise, yet descriptive title Aim: What question(s) are you trying to answer? Background Information: Include any preliminary observations…

Words 3172 - Pages 13

software safety Essay

Asif Syed Summary: Software for safety-critical systems, such as avionic, medical, defense, and manufacturing systems, must be highly reliable since failures can have catastrophic consequences. While existing methods, such as formal techniques, testing, and fault-tolerant software, can significantly enhance software reliability, they have some limitations in achieving ultrahigh reliability requirements. Formal methods are not able to cope with specification faults, testing is not able to provide high…

Words 5167 - Pages 21

Questions On Financial Accounting

Carr, CPA Instructor Email: timothy.carr@strayer.edu Instructor Phone: 901-359-8408 Instructor Office Hours – By Appointment COURSE DESCRIPTION This course provides a framework for financial accounting concepts and practices used by internal and external users in businesses. Topics presented include the accounting cycle, financial reporting, financial statements analysis, ratio calculation and interpretation, and management decision making based on financial results.…

Words 6870 - Pages 28

Chemical Reaction and Copper Sulphate Essay

Introduction. There are many factors that affect the rate of reaction which include: Concentration Temperature Use of Catalyst Surface area Temperature: When you raise the temperature of an element, the molecules bounce around a lot more and give them more energy. When they bounce around more and have more energy, they are more likely to collide. That fact means they are also more likely to combine and react together. When you lower the temperature, the molecules are slower and bump into one another…

Words 2008 - Pages 9

The Four Main Aspects Of Canada's Healthcare System

There are different types of healthcare systems around the world. Each one is operated differently even though they may have similarities. Canada is a country that has a different approach to healthcare than the U.S. does. The comparison of the four main aspects of a healthcare will show which is a more preferable healthcare system. These aspects are: cost, access, quality, and safety. Healthcare costs in Canada are deemed as “free” but in fact they are not due to the high taxation that Canadians…

Words 3279 - Pages 14