Solubility of Organic Compounds

Solubility of Organic Compounds

Yuriann Angelica Pempengco, Alexandra Portillo and Alpha Divina Nolasco1

Chemistry Department, College of Humanities and Sciences, De La Salle Health Sciences Institute, Dasmarinas Cavite

DATE PERFORMED: February 24, 2016

DATE SUBMITTED: March 21, 2016

ABSTRACT

The solubility of the organic compounds is concept of this experiment. This will help to identify the relationship of the functional group to its solubility to the solvent. Dropping 20 drops of different compounds and 3 mL of the solvent was done to test their solubility to each solvent whether it is soluble or insoluble. Each compound has their own group depending on their characteristics. The results depend on the properties of the functional group also the polarity, nature and physical properties of the compound that significantly affects the solubility of the compound.

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Keywords: solubility, functional groups, polarity, solvent

INTRODUCTION

Organic compounds are compounds that contain carbon chains that vary in size and shape. Each carbon atom has 4 as its valence electrons, which means that it is capable of 4 single bonds. These organic compounds can be determined through qualitative analysis that includes the solubility, different properties, acidity or basicity, and functional groups. Knowing the functional group of a compound will help identify its solubility to an organic compound or to water. The simple rule to use when determining the solubility is “like dissolves like.”

These are the compounds present in the experiment: acetone, aniline, benzyl alcohol, benzaldehyde, benzoic acid, benzamide, ethanol, hexane, phenol, sucrose, tert-butyl chloride and toluene.

OBJECTIVES

The main objective of this experiment is to be able to classify each organic compound depending on their solubility to each solvent. The knowledge about “like dissolves like” can be proved in this experiment based on their structure. This also aims to investigate the different properties of the organic compounds on why these compounds are soluble in these kinds of solvents.

METHODOLOGY

In each test tube, distilled water (3ml) was added before 20 drops of acetone, aniline, benzyl alcohol, benzaldehyde, benzoic acid, benzamide, ethanol, hexane, phenol, tert-butyl chloride, toluene and sucrose were put. Each sample was observed if it is completely dissolved or not then grouped to water-soluble and water-insoluble. New test tubes were acquired for the water-soluble and put diethyl ether (3ml) after 20 drops of water-soluble compounds were added. The samples were labeled as S1 if soluble in ether; otherwise S2. Water-insoluble samples (20 drops) were put to new set of test tubes and 5% of NaOH (3ml) was added. The samples were observed and grouped together to 5% soluble in NaOH and not. New test tubes were gathered for samples 5% NaOH soluble (20drops) and 5% of NaHCO3. The samples were labeled as A1 if soluble in 5% NaHCO3; A2 if not. New set of test tubes was obtained for 5% NaOH insoluble (20drops) and placed 5% HCl (3ml). The samples were labeled as B if soluble in 5% HCl and M if sample had N or S. Those samples without N or S (20ml) were placed to new test tubes and put H2SO4 (3ml). If the sample was soluble in H2SO4 label as N if not I.

RESULTS AND DISCUSSIONS

Table 1: Solubility of Organic Compounds

Sample Class distilled

water diethyl

ether 5% NaOH 5% NaHCO3 5% HCl conc. H2SO4

Acetone S1

✓

✓

–

–

–

–

Aniline B ✗

–

✗

–

✓

–

Benzyl Alcohol N ✗

–

✗

–

✗

✓

Benzaldehyde N ✗

–

✗

–

✗

✓

Benzoic Acid A1 ✗

–

✓

✓

–

–

Benzamide M ✗

–

✗

–

✗

–

Ethanol S1 ✓

✓

–

–

–

–

Hexane I ✗

–

✗

–

✗

✗