Liquid resins are converted into insoluble and infusible solids through oxirane reactions. The oxirane structure is referred as epoxy functionality. The resin used in the experiment has a functionality of two. Resins are usually prepared with the reactions of bisphenols –and generally commercially bisphenol A- with epichlorohydrin or glycidyl chloride. Epoxy resins are generally cured with primary/secondary polyamines, anhydrides, and polyamides.
Chemistry 75a | Experiment1: Solubility | George Sayegh | | Dr. Tjandra | 9/3/2013 | | Purpose: To be able to gain a good understanding in solubility behaviors through polarity and Acid-Base techniques. In the experiment we will gain an understanding of the structural futures of a substance that determines its solubility in various solvents. Experimental and Data/Result: Part A: Solubility of Solid Compounds: In this Part A of the experiment we will test the solubility of 3 organic compounds, Benzophenone, Succinic Acid, and Biphenyl in the same method for all three. To each organic compound we will add water (highly polar), Methyl Alcohol (intermediate polar), and Hexane (non-polar). Using these 3 testers we will see the solubility of each organic compound and also how it relates to the
That is why once you add the benzoic acid aqueous solution and the CH2Cl2 in the separatory funnel the benzoic acid moves from the aqueous layer into the methylene chloride organic layer. This will occur until an equilibrium is establish between the aqueous layer and the organic layer; that is there is an equal amount of benzoic acid in the aqueous layer and the organic
Abstract: The ability to isolate caffeine from tea leaves was questioned and was found to be successful in this experiment. This was achieved by extracting caffeine, separating other natural substances and sublimating the existing caffeine. The weight of the caffeine isolated from the tea leaves was .0186g; which is a 33.8% recovery of the original material of caffeinated tea leaves. Introduction: This experiment’s purpose is to extract the caffeine that consists in a small portion of tea leaves. The theory of extraction is a technique used to separate organic compounds from a mixture or a solution of compounds.
ABSTRACT Thin layer chromatography (TLC) is a chromatographic technique used to separate the components of a mixture using a thin stationary phase supported by an inert backing. It may be performed on the analytical scale as a means of monitoring the progress of a reaction, or on the preparative scale to purify small amounts of a compound. TLC is an analytical tool widely used because of its simplicity, relative low cost, high sensitivity, and speed of separation.TLC functions on the same principle as all chromatography, which is, a compound will have different affinities for the mobile and stationary phases, and this affects the speed at which it migrates. The goal of TLC is to obtain well defined, well separated .This paper presents a review of the literature concerning the use of thin layer chromatography to separate the active ingredients of the parsley leaves into its different pigments .The silica gel remains the most important adsorbent for TLC separation.The migration of the different pigments is by capillary forces. Components that are more strongly attracted to the sorbent layer will travel a shorter distance, while components that are more soluble in the mobile phase will travel a longer distance from the origin.To identify possible pigments that are found in Robertson Parsley dry leaves, Thin layer chromatography was perfomed using a solid silica gel plate and a mixture of acetone, chloroform and di ethyl ether in the ratio 1:1:3.
Thin Layer Chromatography in the determination of unidentified analgesics Introduction Chromatography is the process of various techniques that separate mixtures due to the polarity of the substances involved. Chromatography techniques have two different phases, the stationary phase that can be solid or liquid while the mobile phase can be either liquid or gas. Thin layer chromatography (TLC) consists of liquid mobile phase and a solid stationary phase where the adsorption of solutions on the surface of the silica gel aluminium plate occurs (Glencross et al. 2010: 313). Given that silica is an absorbent, TLC is a “form of adsorption chromatography” (Varcoe 2001: 8-1).
Phenolphthalein) is used to show the equivalence point has reached by changing colours. Titration experiments are used to determine the concentration of an acid or a base, if either acid or base concentration known, the other unknown concentration can be find out by measuring how much it takes to neutralize, which is a useful experiment. The Bronsted-Lawry theory about acid and base, describes as follows; an acid a proton (hydrogen ion) donor, a base is a proton (hydrogen ion) acceptor, or any component that can transfer proton to any other component is and acid and any component that accepts the proton is base. The theory says a substance can function as an acid only when a base is presented, and also other way round, a substance can only function as a base in the present of an acid. This theory consider a large
The Fischer esterification works just as fine and is cheaper so why not. Mechanism for Acetylsalicylic acid Overall Reaction [pic] Complete Mechanism (HA- was substituted for H3PO4 to simply the mechanism) [pic] Side Reaction [pic] Experimental [pic] Table of Chemicals Salicylic Acid [pic] Mp: 159 Mm: 138.121 g/mol Mf: C7H603 Appearance: colorless to white crystals Hazards: eye and skin irritant Acetic Anhydride [pic] Mp: -73.1 Mm: 102.09 g/mol Mf: C4H603 Appearance: colorless liquid Hazard: corrosive Acetylsalicylic Acid [pic] Mp: 136 Mm: 180.157 g/mol Mf: C9H804 Appearance: white crystals Hazards: combustile powder if dispersed in the air. Phosphoric Acid [pic] Mp: 42.35 Mm: 98 g/mol Mf: H3PO4 Appearance: white solid or colorless Hazards: possibly corrosive Results Acetylsalicylic acid Mp: 95-105 Color of crystals:
Thin Layer Chromatography Introduction (Adapted from Mohrig, 1st ed., pp. 151-162.) Chromatography is a sophisticated method of separating mixtures of two or more compounds. The separation is accomplished by the distribution of the mixture between two phases: one that is stationary and one that is moving. Chromatography works on the principle that different compounds will have different solubilities and adsorption to the two phases between which they are to be partitioned.
If the solution of water and caffeine is mixed with the solvent dichloromethane, the caffeine is transferred to the dichloromethane. This results from the fact that caffeine is much more soluble in dichloromethane than water. Water and dichloromethane are not soluble in each other. The volatile dichloromethane can easily be vaporized off from the dichloromethane/caffeinesolution leaving fairly pure solid caffeine. In the process the solubilities of cellulose, tannins, and of chlorophyll will be considered.