EXPERIMENT 2 ACID DISSOCIATION CONSTANT OF AN INDICATOR DYE OBJECTIVES Using spectrophotometric method: determine the wavelengths at which the acid and base forms of the dye in aqueous medium exhibit maximum absorption; determine the molar absorptivities of the acid and base forms of the dye and estimate an unknown concentration of the dye in solution using the Beer-Lambert’s Law; and determine the acid dissociation constant of the indicator dye. THEORY The absorption or reflection of
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mixtures and find the dissociation constant of acetic acid Chemistry (HL) Research Question: To determine the pH of various mixtures of sodium acetate and acetic acid in an aqueous solution and hence to find the dissociation constant of the acetic acid. Background: The mixture of sodium acetate and acetic acid in aqueous solution is a buffer solution. Buffer solutions are the solutions which resist a sudden change in the pH due to addition of small amounts of strong acid or base. An acidic buffer
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Date Performed: September 9 ‚2011 SPECTROPHOTOMETRIC DETERMINATION OF THE ACID DISSOCIATION CONSTANT OF METHYL RED M.C. Caligagan ‚M.N.Q. Tolentino and M.Q. Clores Institute of Chemistry‚ College of Science University of the Philippines‚ Diliman‚ Quezon City‚ Philippines Received :September 21‚2011 ABSTRACT This experiment aims to determine the acid dissociation constant value of Methyl Red by means of spectrophotometry. Ten samples were spectrophotometrically analyzed under a UV-Vis
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Synthesis of Salicylic Acid and Potentiometric Determination of its Purity and Dissociation Constant ------------------------------------------------- Abstract The purpose of the study is to synthesize salicylic acid from the ester‚ methyl salicylate‚ and determine the acid’s dissociation constant and purity. The ester was converted to salicylic acid by base hydrolysis. The products were refluxed and recrystallized‚ to ensure maximum purity‚ and filtered‚ dried‚ and weighed. The melting point
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Experiment # 4: Dissociation Constant Weak Acids Introduction: The dissociation constants of weak monoprotic acids were determined with the aid of a buffer and pH meter. Experiment: This experiment was performed according to the procedures as provided in the Chemistry 111B laboratory manual: Po‚ Henry and Senozan‚ N. "General Chemistry Experiments Chemistry 111B"‚ 8th Ed.‚ 2004 Hayden-McNeil Publishing‚ pp 80-88. To determine the dissociation constants of weak monoprotic acids (HX and HY)‚ a buffer
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The Equilibrium Constant of an Ester Hydrolysis Reaction CHM 152LL Section 33263 March 28‚ 2014 John Weide Abstract: The purpose if this experiment is to determine the equilibrium constant of an unknown alcohol. In this experiment unknown alcohol number three and unknown ester number three were used. The equilibrium constant was found by titrating a series of reactions containing H2O‚ HCl‚ and the unknown ester with only the last solution containing the unknown alcohol
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Standardization of NaOH and Determination of Unknown Acid KEYWORDS: quantitative analysis‚ titration‚ buret‚ endpoint‚ standardization‚ half-equivalence point‚ calorimetric titration‚ potentiometric titration ABSTRACT: The concentration of sodium hydroxide was determined by colorimetric titration‚ and the identity of an unknown acid was determined by potentiometric titration. In the first titration‚ a strong acid standard‚ potassium hydrogen phthalate (KHP)‚ was used‚ to determine the concentration
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ACIDS AND BASES The reason that acid-base reactions are so important is that many of the things you come into contact with on a daily basis are either acids or bases. Most fruits are acids‚ as are carbonated beverages‚ tea‚ and battery acid. Common household bases include baking soda‚ ammonia‚ soap‚ and antacids. What are acids and bases? There are not one but three common definitions used to describe acids and bases: 1. Arrhenius acids and bases 2. Brønsted-Lowry acids and bases 3. Lewis acids
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BRONSTED-LOWRY ACIDS AND BASES 1. The Bronsted-Lowry definition There are many definitions of acids and bases in existence‚ but the most useful one is the Bronsted-Lowry definition: An acid is a substance which can behave as a proton (re presented as a hydrogen ion‚ H+) donor. Any substance which contains hydrogen bonded to a more electronegative element can thus behave as an acid: HCl == H+ + Cl- H2SO4 == H+ + HSO4- A base is a substance which can behave as a proton acceptor. Any
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Determination of Equilibrium Constants Introduction Bromothymol blue is an indicator for many acid-base titrations. When adding different solutions within the indicator it is to react and change colors‚ in this experiment the different colors were blue‚ green‚ and yellow. In the following experiment‚ obtaining the absorbance levels for each one makes it possible to calculate the equilibrium constant. Materials and Methods For this specific experiment there are a few materials that are crucial
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