Benzoic Acid and Benzoates in Food‚ Drinks and Medicines Benzoic acid and benzoates are common additives to food‚ drinks‚ medicines and cosmetics‚ and they also occur naturally in many plants. They are useful chemicals in manufactured products because they kill or inhibit both bacteria and fungi and can act as preservatives. Benzoic acid and benzoates are considered to be safe chemicals for humans when they’re used in small quantities‚ but there are at least two situations in which even small
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Unit 4 Assessment 2-Benzoic Acid Synthesis Synthesis and Investigation of Benzoic Acid Our aims: Create benzoic acid using benzaldehyde and hydrogen peroxide. Then remove some impurities from the benzoic acid crystals. Apparatus: Titration Pipette (25 cm3) Burette (50 cm3) Retort stand Clamp Conical flask (250 cm3) Volumetric flask (250 cm3) and stopper White tile Beakers (250 cm3) Dropping pipette Filter funnel Deionised water Phenolphthalein indicator Volumetric flask
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Experiment 11 Title: Spectrophotometric analysis of caffeine and benzoic acid in soft drink. Name: Tan Herh Lim Name of partner: Sia Ting Wai‚ Chong Zheng Yee Date: Lecturer: Dr. Neo Kian Eang Practical class: P1 Objective: To obtain the absorbance of the caffeine and benzoic acid in soft drinks. Introduction Soft drinks that commonly found in our daily life contain caffeine and sodium benzoate. The caffeine act as a stimulant and the sodium benzoate acts as a preservative
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Acid-Base Extraction: Separation of an Organic Acid‚ Base and a Neural Compound Introduction/Background Acid base extraction is a widely used commercial method in separating acids‚ bases and neutral compounds. This is concept is based on several physical properties of the compounds‚ such as boiling point‚ melting points and solubility. The different solubility properties of the protonated and non-protonated forms of these compounds depend on the functional groups present‚ such
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Lab 5 Acid/Base Extractions Introduction The purpose of this experiment is to separate either the organic base (amine) or organic acid (carboxylic acid) from a mixture that contains inorganic impurities (salt) by performing a liquid-liquid extraction and then taking a melting point. Key Experimental Details and Observations Our starting material‚ Compound B‚ was a fine white powder and weighed 0.535g. The final product was a shiny white sheet that resembled acrylic paint and weighed 0.109g
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Objective: The objective of this experiment is to use acid-base extraction techniques to separate a mixture of organic compounds based on acidity and/or basicity. After the three compounds are separated we will recover them into their salt forms and then purify them by recrystallization and identify them by their melting points. Procedure: Extraction of Carboxylic Acid A pre-weighed (0.315g) mixture of Carboxylic acid‚ a phenol‚ and neutral substance was placed into a reaction tube (tube 1)
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CHM456 ORGANIC CHEMISTRY 1 LABORATORY Contact hours: 3 hours/week Laboratory textbook: Pavia‚ Lampman‚ Kriz and Engel‚ Introduction to Organic Laboratoy Techniques 3rd Edition (2011) ** Students MUST obtain a copy of the textbook Synopsis This is an organic chemistry practical course which reinforce the theory and concepts studied in Organic Chemistry 1 (CHM456). It covers the learning of simple laboratory techniques such as reflux‚ distillation‚ extraction‚ crystallization and melting point
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EXPERIMENT 2: Recrystallization and Melting Point Recrystallization (or Crystallization) is a technique used to purify solids. This procedure relies on the fact that solubility increases as temperature increases (you can dissolve more sugar in hot water than in cold water). As a hot‚ saturated solution cools‚ it becomes supersaturated and the solute precipitates (crystallizes) out. In a recrystallization procedure‚ an impure (crude) solid is dissolved in a hot solvent. As this solution is cooled
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BENZOIC ACID & BENZOATES (210 –218) • Retards growth of bacteria and yeasts • Occurs naturally in many foods – a similar distribution to salicylate (but at a lower dose than as an additive) • Common food sources: Soft drink‚ cordial‚ fruit juice and cider Liquid essences and syrups Iceblocks‚ jelly‚ low joule jam‚ dips‚ pickles‚ olives Fish marinades and preserves • PABA (para-amino-benzoic-acid)
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isomers of α-phenylcinnamic acid. This was accomplished by refluxing benzaldehyde‚ phenylacetic acid‚ acetic anhydride and triethylamine as a base. The chemical equation of a Perkin Reaction can be seen below. The reaction mechanism for the synthesis of α-phenylcinnamic acid is shown below: Results: Theoretical Yield Therefore‚ phenylacetic acid is the limiting reagent. Table 1. Literature and actual IR values of (E) and (Z) isomers of α-phenylcinnamic acid. Compound Literature
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