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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Sodium borohydride Reduction of Benzil Introduction: The Purpose of this experiment is for the students to learn how to use sodium borohydride to reduce benzil to its secondary alcohol product via reduction reaction. This two-step reaction reduces aldehydes by hydrides to primary alcohols‚ and ketones to secondary alcohols. In order for the reaction to occur and to better control the stereochemistry and yield of the product‚ the metal hydride nucleophile of the reducing agents such as LiH‚ LiAlH4
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Introduction Extraction is a purification technique used in organic chemistry to separate compounds from a mixture of two or more compounds. There are three different extraction techniques: liquid-liquid extraction‚ solid-liquid extraction and chemically active extraction. All three types of extraction follow the same principle. Organic molecules dissolve in organic solvents and polar molecules dissolve in aqueous solvents. This phenomenon is observed because of the intermolecular forces between
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Investigating the Ratio Between Poly-Vinyl Alcohol and Sodium Borate to form a Bouncing Ball Timothy English Gen. Chem. 1 Lab Section: 009 Introduction: Poly-Vinyl Alcohol (PVA) is a water-soluble synthetic polymer that will be used as one element to form the well know bouncing ball‚ along with Sodium Borate (borax)‚ which has a variety of uses because of its weak base. PVA is ideal for this experiment because it is odorless‚ nontoxic‚ has high tensile strength and flexibility. The
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one of two very similar pentose rings. Ribonucleic acids contain the sugar ribose. Deoxyribonucleic acids contain the sugar deoxyribose. The only difference between these two sugars is that deoxyribose contains one oxygen atom less than ribose. Pentose sugars are essential because they are involved in linking different nucleotides together by condensation reactions. The Nitrogen-Containing Bases There are two types of bases found in nucleic acids. The purine bases have two nitrogen containing rings
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Chapter 13 Acids and Bases (Dr Chong Fai Kait) 1) A 7.0 103 M aqueous solution of Ca(OH) 2 at 25.0 °C has a pH of __________. A) 12.15 B) 1.85 C) 1.4 102 D) 7.1 1013 E) 11.85 Answer: A 2) The acid-dissociation constant at 25.0 °C for hypochlorous acid (HClO) is 3.0 108 . At equilibrium‚ the molarity of H 3 O in a 0.010 M solution of HClO is __________. A) 1.7 105 B) 0.010 C) 5.8 1010 D) 4.76 E) 2.00 3) Using the data in the table‚ which of the conjugate acids below is the weakest
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ids Acids‚ Bases‚ Buffers and Respiration Darlene E. McDonald WCCC Fall 2012 Ap Lab 071-07 Dr. Roxanne Levandosky August 31‚ 2012 I. INTRODUCTION: A.PURPOSE: a. To define and understand the key terms. ~acid ~buffer system ~base ~acidosis ~pH ~alkalosis ~pH scale ~hypoventilation ~pH indicators ~hyperventilation b. To determine the acidic or base nature and actual pH of various substances. c. To discuss the formation of the carbonic acid/bicarbonate ion
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Flowers and Acid Call them freaks‚ the underground‚ the counterculture‚ flower children‚ or just simply hippies‚ they are all loose labels for the youth culture of the 60’s that transformed life in the West as we knew it‚ introducing the spirit of freedom‚ of hope‚ of happiness‚ of change‚ and of revolution (Miles 9). The years that made up the 1960’s were some of the most exciting and turbulent years in American history. The post World War II baby boomers grew up. A president and
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1. Introduction 2 2. Graphs 2.1 HC2H3O2 titration curve 3 2.2 H3PO4 titration curve 4 2.3 H2A titration curve 5 3. Calculations 3.1 HC2H3O2 Calculations a. Exact molarity of the HC2H3O2 solution 6 b. Ka from the initial pH 6 c. Ka from the pH at halfway point 6 d. Ka from the pH at the end point 7 3.2 H3PO4 Calculations a. Exact molarity of the H3PO4 solution 7 b. Ka1 from
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Solution Name Color Description Known 1 Barium Green Known 2 Calcium Red Known 3 Sodium Yellow Known 4 Rubidium Purple Known 5 Potassium Blue Known 6 Lithium Pink Unknown Sodium Yellow Unknown Potassium Blue The first unknown is sodium because it has a yellow flame. The second unknown is potassium because it has a blue flame. Part 2: Hydrogen Helium Sodium Neon Mercury Star 1 Purple‚ 410 Blue‚ 449 Yellow‚ 579 Purple‚ 420 Blue‚ 430 Aqua
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