Experiment 6 - Comparative Investigation Of Organic Compounds Formal Report 3e5g2i

COMPARATIVE INVESTIGATION OF ORGANIC COMPOUNDS Harvie M. Barcellano, Dariene Joie B. Bautista, Florianne May D. Beltran, Jerika Prem M. Benjamin, Rochelle Anne C. Burata and Emmanuel R. Caliwag Group 2 2G Medical Technology Organic Chemistry Laboratory ABSTRACT

The objective of the experiment is to differentiate organic compounds in of certain intrinsic physical properties, behavior towards ignition test, and infrared spectra of their functional groups. Physical properties are determined by observing the samples’ physical state at room temperature, color and odor. Solubility and miscibility were tested using the following reagents: water, 5% NaOH solution, and 5% HCl solution. Only dichloromethane appeared to be immiscible in the three solvents, the rest being slightly miscible or miscible. Acidity and basicity of the compounds were determined by the use of litmus paper. Only phenol and benzoic acid was observed to be acidic, while ethylamine as the sole basic compound, the rest being neutral. Ignition test was also conducted, taking note of the flame produced if flammable. Among the samples, only dichloromethane, phenol, and benzoic acid were identified to be non-flammable. Infrared spectroscopy, which is useful for determining the functional groups present in an organic compound, was used to find the IR peaks of each sample. From the experiment, it could be concluded

that organic compounds have different properties and that the types of bond and functional groups of these organic compounds affect those properties. INTRODUCTION Generally, organic compounds can be classified into hydrocarbons and hydrocarbon derivatives, based on the replacement of hydrogen by another element or by a group of different elements. Specifically, organic compounds are conveniently classified as different classes of hydrocarbon derivatives based on the substituent element or group of highest priority to the hydrocarbon. Functional groups present in an organic compound can be determined using infrared spectroscopy[1]. Organic compounds are the complex compounds of carbon. Because carbon atoms bond to one another easily, the basis of most organic compounds is comprised of carbon chains that vary in length and shape. Hydrogen, nitrogen, and oxygen atoms are the most common atoms that are generally attached to the carbon atoms. Each carbon atom has 4 as its valence number which increases the complexity of the compounds that are formed. Since carbon atoms are able to create double and triple bonds with other atoms, it further also raises the likelihood for variation in the molecular make-up of organic compounds. Hydrocarbons are the simplest class of organic compounds and are composed solely of hydrogen and carbon. This class can be further divided into two groups: aliphatic hydrocarbons and aromatic hydrocarbons. Aliphatic hydrocarbons can be classified based on the structure and bonding of the carbon skeleton into three groups: alkanes, alkenes, and alkynes. Aromatic hydrocarbons or arenes, which contain a benzene ring, were originally named for their pleasant odors. These compounds possess special properties due to the

delocalized electron density in benzene, including additional stabilization due to the system of conjugated rings consisting of unsaturated bonds, lone pairs, and empty orbitals[3]. Organic compounds possess different physical properties, which are intrinsic[1]. They may vary in their physical state at room temperature, which can indicate the strength of interactive forces that exist between its molecules, color, odor and solubility indifferent reagents. The experiment aims to differentiate organic compounds in of: certain intrinsic physical properties, behavior towards ignition, and infrared spectra of their functional groups. Cond ensed structural formula of the compounds used[2]: 1. Cyclohexane

2.DCM CH2Cl2

3. Ethanol CH3CH2OH

Drops of the sample tested its aqueous solution with red and blue litmus papers. Color changes with both litmus papers were noted.

4. Phenol

5. Benzoic Acid

4. Ignition Test 3-5 drops of the liquid and pinch amount of solid sample were placed in a small evaporating dish and lighted with a match stick. Any flame produced and observed was noted. The color of the flame and burning time were also noted. 5. Infrared (IR) Analysis The type of principal bonds of each sample compound was identified. The book, Reference 1, was used as a guide in determining the wave number range of each organic compound, as well as its intensity.

RESULTS AND DISCUSSION

6. Ethyl Acetate

7. Ethylamine CH3CH2NH2

EXPERIMENTAL A. Compounds Tested Cyclohexane, Dichloromethane, Ethanol, Phenol, Benzoic acid, Ethyl acetate, and Ethylamine B. Procedure 1. Physical State, Color and Odor The physical state of the sample was observed in room temperature. Color and odor was noted. 2.Solubility Properties The samples were introduced into clean and dry test tubes. Four drops of each sample were introduced if the sample is a liquid; and 0.1 g of the sample was introduced if the sample is solid. The solid samples were grinded to increase the surface area. The solvent was added drop wise, counting the number of drops of solvent added to a total of 3 mL. Any color changes, warming or effervescence, soluble/insoluble, miscible/immiscible were noted. 3. Reaction with Litmus Paper

All of the hydrocarbons tested were colorless, except phenol, which is orange in color, and benzoic acid which is white in color. The odors of the compounds were quite similar but it has its unique differences that can be seen on Table 1. Solubility test is done to be familiar with the chemical nature of the compounds. Water, 5% NaOH and 5% HCl were used to describe the compounds' solubility properties and miscibility. Based on the results, cyclohexane was observed to be miscible in water, and slightly miscible in 5% NaOH and 5% HCl; DCM appeared to be immiscible in the 3 solvents; ethanol, phenol and ethylamine were miscible in the 3 solvents; benzoic acid, miscible in water, slightly miscible in 5% NaOH and 5% HCl; Ethyl acetate was immiscible in water and 5% NaOH, and was miscible in 5% HCl. Reactions with litmus paper indicate the acidity/basicity of water-soluble samples. If a blue litmus paper turns into red, then the sample is acidic, but when a red litmus paper turns into blue, then the sample is basic. The litmus paper that retains its color indicates a neutral compound. Based on the experiment, cyclohexane, dichloromethane, ethanol, and ethyl acetate appeared to be neutral. On the other hand, phenol and benzoic acid was observed to be acidic and ethylamine as the sole basic compound. Solubility of organic compound also indicates acidity and basicity of the sample. The result of ignition test indicates the presence of unsaturation or high carbon to hydrogen ratio. Among the samples, only dichloromethane, phenol, and benzoic acid were identified to be non-flammable. The degree of luminosity can be assessed by the presence of yellow flame and soot. The aromatic compounds burn with sooty flame due

to complete combustion which causes the formation of an unburned carbon. In of degree of luminosity: aromatic compound>unsaturated hydrocarbon> saturated hydrocarbon. Complete combustion is indicated by a blue flame (non luminous) and there is more heat than light, the carbon is completely oxidized. 2 C10H22 + 31 O2

→

20 CO2 + 2 H2O

Incomplete combustion is indicated by a yellow flame (luminous) and there is much light than heat, the carbon is not completely oxidized. [1] Infrared spectroscopy is particularly useful for determining the types of bonds that are present in a molecule. The primary use of IR is to identify the functional groups present in a molecule. From the experiment, it could be concluded that organic compounds have different properties and that the types of bond and functional groups of these organic compounds affect those properties.

REFERENCES: [1] Bathan, G.I., Bayquen, A.V., Crisostomo, A.B.C., Cruz, C. T., De Guia, R.M., Farrow, F.L., Peña, G.T., Sarile, A.S., Torres, P.C. (2014). Laboratory Manual in Organic Chemistry. Manila: C&E Publishing, Inc. P.69 [2] Formulas of Inorganic and Organic Compounds. (n.d.). In ChemWiki. Retrieved November 20 2015 from http://chemwiki.ucdavis.edu/Physical_Chemistry/ Quantum_Mechanics/09._The_Hydrogen_Atom/A tomic_Theory/Chemical_Compounds/Formulas_of _Inorganic_and_Organic_Compounds [3] What are Organic Compounds?. (n.d.). In wiseGeek. Retrieved November 20, 2015 from http://www.wisegeek.com/what-are-organiccompounds.htm

Table 1. Comparative Investigation of Organic Compounds Test Compounds

Cyclohexane

DCM

Ethanol

Phenol

Benzoic acid

Eth

Physical State at RT

Liquid

Liquid

Liquid

Liquid

Solid

Liq

Appearance

Clear

Clear

Clear

Clear

Crystalline

Cle

Color

Colorless

Colorless

Colorless

Orange

White

Col

Odor

Diesel-like odor

Kerosene-like odor

alcohol-like odor

Burnt plastic-like odor

Odorless

Pla odo

Solubility in H 2O

Miscible

Immiscible

Miscible

Slightly miscible

Slightly soluble

Slightly miscible

Immiscible

Miscible

Miscible: orange to violet

Soluble

Slig mis bub Mis

Slightly miscible

Immiscible

Miscible

Miscible: orange to white

Slightly soluble

Mis

Reaction with litmus paper

Blue to Blue Red to Red

Blue to Blue Red to Red

Blue to Blue Red to Red

Blue to Red Red to Red

Blue to Red Red to Red

Blu Red

Ignition test

Flammable: yellow-orange

Non-flammable

Flammable: blue and orange

Non-flammable

Non-flammable

Fla ora

Observed principal IR peaks (cm-1)*

C-C stretch: 1200-800, very W C-H bend: 1435-1350, S-M C-H stretch: 3000-2840, S

C-Cl: 580-780, S C-C stretch: 1200-800, very W C-H stretch: 3000-2840, S

O-H stretch: 3700-3100, very S O-H bend: 14201340, M-W C-O stretch: 1230-1000, S-M C-C stretch: 1200-800, very W C-H stretch: 3000-2840, S C-H bend: 14751350, S-M

O-H stretch: 3700-3100, very S O-H bend: 14201340, M-W C-O stretch: 1230-1000, S-M C=C ar. stretch: 1620-1480, M-W C-C stretch: 900600, S-M C-H stretch: 3100-3000, M-W

C=C ar. stretch: 16201480, M-W C-H stretch: 3100-3000, MW O-H stretch: 3300-2500, broad S O-H bend: 1440-1390, M C=O stretch: 1730-1680, S C-O stretch: 1320-1210, S

C= 174 C-O 124 C-H 300 C-H 147 M C-C 120 ver

5% NaOH soln. 5% HCl soln.

[1]

*S = strong, M = medium, W = weak