Effects of curing condition of solution cast Nafion® membranes on PEMFC performance Korean J. Chem. Eng.26(3)‚ 679-684 (2009) Thickness of membrane ~ 50µm There are some disadvantages of the solution casting method that the cold cast films are generally mechanically weak‚ susceptible to crack formation and soluble in many polar solvents‚ especially in water at room temperature. Generally‚ the annealed films undergo morphological changes when heated above the glass transition temperature (Tg=109oC
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Extraction (Ch # 07) Faraz Gohar Mr. Wayne Xie Chem 201 10/02/2012 Objectives : 1)To purify samples of organic compounds that are solids at room temperature. 2)To dissociate the impure sample in the minimum amount of an appropriate hot solvent Chemical Index : Naphthalene; mp 82 *C 1‚4-Dichlorobenzene; mp 56 *C 4-Chloroaniline; mp 68 - 71 *C; pKb 4.15 Ethyl 4-Aminobenzoate; mp 90 *C; pKb 4.92 Procedure :
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Abstract: Caffeine‚ (C8 H10 N4 O2) a white‚ crystalline alkaloid known as a nervous system stimulant found commonly in tea leaves and coffee‚ can be extracted using the method of sublimation with the use of Methylene Chloride (CH2Cl2) and Sodium Hydroxide; both can repeatedly rinse the green (unroasted) coffee beans from the caffeine. Keywords: Caffeine‚ Methylene Chloride‚ Sodium Hydroxide‚ Anhydrous Sodium Sulfate I. Introduction Caffeine is an alkaloid of the methylxanthine family. Its chemical
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is unknown. The unknown component is suspected to be a chemical relative of acetaminophen‚ either acetanilide or phenacetin. Using techniques such as extraction‚ evaporation‚ and filtration‚ the three components will be isolated based on their solubilities and acid-base properties. Then‚ the percent composition of Panacetin can be deduced based on the masses of the three dried components. The compounds being studied are as follows: Calculations Theoretical Percent
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future experiment that can be performed to try and identify this red solution is to obtain 50 mL of red solution #2‚ a graduated cylinder‚ ten 50 mL beakers‚ a scale‚ a stir bar‚ and different elements that are known to be insoluble using a common solubility chart such as one found here: http://www.flinnsci.com/store/Scripts/prodView.asp?idproduct=16645. Measure equal amounts of Red #2 into each of the beakers‚ then
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EXPERIMENT TWENTY Qualitative Analysis of Anions Analysis of Solutions Containing the Ions Cl-‚ Br-‚ l-‚ SO42-‚ CO32-‚ and NO3- This experiment continues the qualitative analysis begun in Experiment 19. Here we will be analyzing solutions to determine the presence of anions. The same techniques that were used for the cation analysis must be used for the anions. If you have not carried out Experiment 19‚ read the introductory section before starting this experiment. The major difference
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Progress in Organic Coatings 50 (2004) 75–104 Review Antifouling technology—past‚ present and future steps towards efficient and environmentally friendly antifouling coatings Diego Meseguer Yebra‚ Søren Kiil∗ ‚ Kim Dam-Johansen Department of Chemical Engineering‚ Technical University of Denmark‚ Building 229‚ DK-2800 Kgs. Lyngby‚ Denmark Received 28 January 2003; accepted 15 June 2003 Abstract The imminent ban of environmentally harmful tributyltin (TBT)-based paint products has been the
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Purpose: The purpose of this experiment was to be able to apply our knowledge of chemistry to identify 10 unknown elements that were presented to us. We were allowed to use Bunsen burners‚ hydrochloric acid‚ use PH paper to test if the unknown solution is an acid or a base‚ and precipitate each unknown solution with each other. Procedure / Data / Conclusions: Unknown #1: I found solution 1 to be KI. While doing the precipitate reactions‚ I found that it precipitates
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OBJECTIVE The main objective of this experiment is to carry out qualitative analysis to identify metal cations in unknown solution 1. INTRODUCTION An unknown material can be determined by using simple chemical tests and separations which is called as inorganic qualitative analysis. The separation of cations depends on the difference in their propensity to form precipitates. Separation scheme is used to classify cation into five groups on the basis of their physical and chemical behavior opposed
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Abstract The purpose of this experiment was to perform a liquid-liquid extraction method to extract the caffeine from the tea bags that were provided‚ and then recrystallize the caffeine. The solvents used in the experiment were an aqueous sodium carbonate and dichloromethane (DCM). Anhydrous calcium chloride pellets were used to dry the solution and emulsion layer and the DCM was then decanted. After washing the anhydrous calcium chloride pellets with more DCM‚ the solvent was evaporated‚ leaving
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