The purpose of my experiment was to research and determine why the odor changed after mixing several controlled substances. The experiment involves esterification, which is the reaction of carboxylic acids and alcohol's to form esters. First, I put 4 ml of vinegar in a test tube and noted the odor, I then added 1 ml of ethyl alcohol and noted the odor. Lastly, I was to add seven drops of sulfuric acid while stirring over a Bunsen burner. I then repeated this process with salicylic acid and methyl alcohol. In this project, my main objective was to accomplish why the odor changed after my mixtures were warmed. My hypothesis for this experiment was that the different smelling chemicals, after being mixed together and heated, would bond together and the molecules would heat up, reacting with each other and giving off special scents.
As you will see, it took a lot of researching to come up with the correct answer and see if my hypothesis was correct. I first had to research all of my chemicals and note their specific contributions to the experiment. The chemicals included vinegar, ethyl alcohol, sulfuric acid, salicylic acid, and methyl alcohol.
RESEARCH OF THE PROBLEM
To start my project, I researched vinegar. Vinegar is a sour liquid with a pungent odor, containing acetic acid, and is made by fermenting dilute alcoholic liquids such as cider, wine, or other fruit juice. Vinegar is used as a condiment, preservative, and in certain medicines (2: 1214).
Ethyl Alcohol is also used in medicines. The formula for this is C2H5OH. It is a colorless liquid with mild characteristic odor. Also known as ethanol, the compound is miscible in all proportions with water or ether (1: 361-362). When ignited, ethyl alcohol burns in air with a pale blue, transparent flame. While burning, it produces H2O and CO2. The vapor forms an explosive mixture with air and is used in some internal combustion engines under compression as a fuel (2: 478-479).
Natural fermentation is the oldest process for making ethyl alcohol and still constitutes the principle means for creating the alcoholic content in beverages. Except in connection with other alcohol containing products, industrial producers of ethyl alcohol use processes other than fermentation. For fermentation, almost any agricultural raw material with a carbohydrate content in the form of sugars or starches that easily convert to sugar can be used. Once the raw materials are in the form of sugars, yeast enzymes are added to commence natural fermentation (1: 361). Traditionally, in the United States, industrial alcohol prepared by fermentation has used blackstrap molasses, which contains up to 50% sugars and can be easily fermented. The starting mash is prepared by diluting it with water to bring the sugar content down to about 15% in weight. The mash is slightly acidified, after which invertase (an enzyme to covet sucrose) and zymase (an enzyme to covert glucose and fructose) are added (3: 589-591). The products are ethyl alcohol and CO2.
My next chemical to research was sulfuric acid. Sulfuric acid or H2SO4, is a colorless, oily liquid. It is dense, highly reactive, and miscible with water. Much heat is evolved when concentrated sulfuric acid is mixed with water and, as a safety precaution to prevent sputtering, the acid is poured into the water rather than vice versa (1: 909-910). Sulfuric acid will dissolve most metals.
There are numerous commercial and industrial uses for sulfuric acid and these include the manufacturing of fertilizers, chemicals, inorganic pigments, petroleum refining, making of explosives, and in nonferrous metallurgy (1: 909). Fundamentally, there are two kinds of sulfuric acid plants. Those that use dry gas (sulfur burning) process, and those that use the wet gas process. In the first type, the raw materials are elemental sulfur and water. In the second type, the sulfur dioxide feed may come from a variety of sources. These sources include metallurgical smelters, pyrite roasters, waste acid decomposition furnaces, and hydrogen sulfide burners. In these plants, the SO2 gas stream enters the acid plant containing a large amount of water vapor. The gas is usually hot and dusty, and may also contain a number of impurities that could harm the catalyst in the contact section of the plant (1: 909-910).
Of the approximately 40 million tons of sulfuric acid manufactured in the United States per year, about 90% is used in the production of fertilizers and other inorganic chemicals. Much of the remaining 10% of H2SO4 is used by the petroleum, petrochemical, and organic chemical industries (2: 1104).
The next chemical is salicylic acid. Salicylic acid or C6H4 (OH)(COOH) is a white solid, which has a melting point at 159 degrees Celsius, it sublimes at 76 degrees Celsius, it is insoluble in cold water, and is soluble in hot water, alcohol, or ether (1: 838). Salicylic acid may be obtained by two ways. The first is from oil of wintergreen, which contains methyl salicylate. The second way is by heating dry sodium phenate plus carbon dioxide under pressure at 130 degrees Celsius, and recovery from the resulting sodium salicylate by addition of dilute sulfuric acid. Salicylic acid is a mild disinfectant and antiseptic that has been used as a food preservative. Salicylic acid and certain salicylates are used in medicine as anti-rheumatics (1: 838).
The last chemical that I had to research was methanol, which we better know as methyl alcohol. Methyl alcohol is a clear, colorless, mobile, highly polar liquid. It's miscible with water, different alcohol's, and ether. When ignited, methyl alcohol burns in air with a pale blue, transparent flame, producing H2O and CO2. The vapor forms an explosive mixture with air (4: 570-571). Methyl alcohol possesses distinct narcotic properties. It is also a slight irritant to the mucous membranes. The principle toxic effect is exerted on the nervous ...