The identification of the melting point of the organic acid was done to find another characteristic of the acid and to test the purity of the recrystallized pure acid. A 2-4 mm layer of unknown sample was placed into a capillary tube sealed on one end. Then the capillary tube was inserted into the side a Bibby Sterlin device. The plateau was set to 200°C on the melting point apparatus. Once the plateau temperature was reached, the sample was watched carefully. When the sample first began to melt and when it was fully melted was recorded. These numbers were the range of the melting point. A slow melting point of the unknown organic acid and a standard sample was completed next. A new plateau was set about 10°C lower than the observed melting point of the unknown sample. This time once the plateau was reached, the heating was no more than 1°C per minute. This gave a much more accurate read of both melting points. If the standard did not melt in the range listed on the label of the bottle, that meant the machine was not working properly. The standard sample and the unknown organic acid melted in their appropriate ranges.…
A 125 mL flask was obtained. The square of aluminum was fashioned over the flask by laying the foil over the mouth and folding the sides down. A pin was then obtained and was used to poke a tiny hole in the center of the aluminum cap.…
2. To determine the densities of water, an unknown liquid, a rubber stopper, and an unknown rectangular solid.…
| LabRepQuiz010 Question MC #7: Which of the following is the best written sentence that includes the information below taken from an article written by Dr. Costanza, but avoids plagiarism?…
The objective of the experiment was to determine the density of a metal along with the density of distilled water. In an attempt to help the experimenters more thoroughly understand the relationship between concentration and density.…
When holding test tube inverted over heptane flame, condensation formed against top walls of the test tube. When the burning splint was added the walls of the test tube became less foggy from the condensation formed from the heptane flame.…
Purpose: In this experiment I will determine the mass, density, volume, lengths and temperatures of different objects and liquids to help me better understand the importance of Chemistry and how Chemistry plays a big role in our everyday lives.…
A. Create a solubility curve for NH4Cl by plotting g NH4Cl/100 mL H20 on the y-axis, and crystallization temperature on the x-axis. Make sure to label each axis. On the same graph as the solubility curve for NH4Cl, add the solubility curve for NaCl using the data provided in Data Table 3.…
.2400 grams of the unknown compound. This is done in duplicate and purple-tinted precipitates are placed in Gooch crucibles. The precipitates are suction dried using ethyl alcohol then acetone to…
Objectives: 1. To examine a variety of reactions including precipitation, acid-base, gas forming, and oxidation-reduction reactions. 2. To identify the products formed in these reactions and summarize the chemical changes in terms of balanced chemical equations and net ionic equations. 3. To identify the species being oxidized and reduced in oxidation-reduction reactions and determine which species is the oxidizing agent and the reducing agent. Chemical equations represent what occurs in a chemical reaction. For example, the equation HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l) describes an acid-base reaction, a type of exchange reaction in which the driving force is the formation of water. In an exchange reaction, the…
This experiment was performed to demonstrate a cycle of chemical reactions involving copper. This lab will start with copper as a reactant in the first reaction through a series of five chemical forms of aqueous phase reactions and ending to calculate the percentage of recovered solid copper as a product in the last reaction of the experiment. The experiment resulted in a percent recovery from the cycle of copper reactions of an increase to 139%.…
This aim of this experiment was to determine whether or not a chemical reaction occurred after the mixing of various chemicals. The evolution of a gas, the formation of precipitation, and the change of temperature or color are all indicative of a chemical reaction. It was assumed that a reaction did not take place if the mixture of chemicals exhibited none of these characteristics. Several precipitation, complex-ion formation, redox, and acid-base reactions were performed.…
0.8 mg. per kilogram, was given. The pupil contracted maximally during the experiment, and dilated only after the second…
The purpose of this lab is to identify an unknown aldehyde or ketone substance using chemical tests. The chemical tests used in this experiment are solubility, Schiff, Bisulfite, and Iodoform tests. Also, a 2,4-dinitrophenylhydrazone derivative synthesis reaction will be completed from which a melting point will be obtained. The chemical test results and the melting point analysis will be compared to the table of compounds given to find the unknown’s identity1.…
In this lab my group and I tested to see how yeast would react to different substances. Yeast is a fungi that releases carbon dioxide which can be used in the process of bread making. During this lab we used sugar, warm water, cornstarch, yeast, a gas sensor, plastic cylinders, and a laptop. The process of this lab was to create cellular respiration, which is what cells do to break up sugars into a form that the cell can use as energy. When yeast and a certain substance were combined, this substance together would release a certain amount of oxygen, this varied over the course of six minutes. We tested the yeast a total of four times using the gas sensor each time. The gas sensor would be left in the bottle for at least six minutes. The oxygen…