“Investigation for an unknown substance”


      An Investigational Project for the
Partial Fulfillment of Requirements in...
Abstract of Study


The Study is intended for the identification of an unknown substance
 which is provided by the instruc...
METHODOLOGY AND RESULTS

Physical Tests

1. Ignition test


A small amount of substance
(preferably 1 drop) is put into a ...
and Water. 1 ml of the unknown
substance is dissolved in 3ml of each
compounds.
Chemical Test                             ...
ANALYSIS AND CONCLUSION

    The unknown substance’s physical characteristics are the key
    element in determining the c...
Investigation For An Unknown Substance
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Investigation For An Unknown Substance

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Investigation For An Unknown Substance

  1. 1. “Investigation for an unknown substance” An Investigational Project for the Partial Fulfillment of Requirements in Organic Chemistry Submitted by: Daniel Thomas A. Berberabe BSP-2A Centro Escolar University Submitted to: Mrs. Gliceria Masicap
  2. 2. Abstract of Study The Study is intended for the identification of an unknown substance which is provided by the instructor. The purpose of the study is to apply different tests and methods learned from Organic Chemistry 11 in detecting the functional group and compositions of unknown substances provided. Based on physical tests, The unknown substance provided by the instructor was a colorless liquid with a characteristic sweet odor. It is highly volatile and flammable. Care must be exercised in handling the substance due to possible fire hazards. The first physical test used is the ignition test which confirmed that the substance is highly flammable. The odor was tested using the wafting method to determine the characteristic odor of the substance (Wafting method is important so that mild irritations associated with chemicals can be avoided). Solubility of the substance was tested in Ethyl Alcohol, Acetone and water. The substance was insoluble in water and soluble in both Ethyl Alcohol and Acetone. The last physical test is the test for Boiling point. The test for the boiling point was done three times yielding an average of 78 degrees Celsius. Based on the results of the physical tests, the unknown substance exhibits properties similar to an ester. The odor of the substance also resembles an acetate group because of its similarities with paint, lacquers and plastic balloon odors. To validate the theory of the compound being an ester, hydroxamic test for esters is employed. The hydroxamic test for the unknown substance provided positive results and confirmed that the substance is an ester. To further recognize the specific composition of the ester, the physical tests were linked with some examples of acetate groups widely used in paints, lacquers and plastic balloons. The final result confirmed that the unknown substance was ETHYL ACETATE
  3. 3. METHODOLOGY AND RESULTS Physical Tests 1. Ignition test A small amount of substance (preferably 1 drop) is put into a Water SLIGHTLY watch glass. The substance is SOLUBLE Ignited using a lighted matchstick. The substance burned with a yellow flame. Acetone SOLUBLE Ethyl Alcohol SOLUBLE 2. Wafting method (odor test) The compound is held near the 4. Boiling point Nose avoiding direct contact and slowly wafting so that the odor can be easily detected. The substance 1st TRIAL 80 degrees contains a sweet odor similar to Celsius paints, lacquers and plastic balloon. 2nd TRIAL 77 degrees 3. Solubility Celsius The solubility of the substance is tested with Ethyl Alcohol, Acetone 3rd TRIAL 78 degree Celsius
  4. 4. and Water. 1 ml of the unknown substance is dissolved in 3ml of each compounds. Chemical Test AVERAGE- 78 degrees celsius 1. Hydroxamic test for esters a.) Preliminary test 1 drop of the unknown substance is dissolved in 1ml of 95% ethyl alcohol and 1ml of 1N HCl. By adding 1 drop of 5% FeCl3,the substance will produce a yellow color. b.) Final test 1 drop of the unknown substance is Mixed with 1ml of hydroxylamine HCl Saturated alcoholic solution and adding 0.2ml of 6N NaOH. The mixture is Heated in a water bath. The mixture Is cooled slightly after heating. By adding 2ml of IN HCl and 5% ferric chloride, a Magenta or burgundy color is produced The magenta or burgundy color produced Compared to the yellow color of the Preliminary test is a positive result. The Unknown substance is an ester
  5. 5. ANALYSIS AND CONCLUSION The unknown substance’s physical characteristics are the key element in determining the composition of the compound. The chemical test however is vital to prove that the unknown substance is an ester. Esters with low molar mass and derived from carboxylic acids are generally flammable that is why the compound ETHYL ACETATE is positive in the ignition test because ethyl acetate is a low molar mass ester and it is also derived from acetic acid and ethanol. One of the main characteristics of ethyl acetate is its sweet odor similar to plastic balloons, this sweet odor is present if the ester has lower molar mass. Solubility is also a good test for determining an unknown compound. Ethyl acetate is slightly soluble in water and soluble in ethanol and acetone. Ethyl acetate is slightly soluble in water because of absence of –OH group and an increase in carbon chain length. Boiling point is the test that specifically identifies the unknown compound because the acetate groups have definite boiling points. Based on the experimental result, the unknown substance yield an average 78 degree Celsius boiling point close to the theoretical boiling point of ethyl acetate. The hydroxamic test for ester is a chemical test used to prove that the unknown substance is an ester. The test is used when an ester is reacted with a hydroxylamine hydrochloride saturated alcoholic solution to and then reacting with ferric chloride to form a ferric hydroxamate which is an indicator that an ester is present. These evidences lead to the conclusion that the unknown substance is ethyl acetate because of the solid evidences provided by physical tests such as boiling point, solubility and the hydroxamic test.

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