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Category : Chemisty

Carbonate Alkalinity Determination

Introduction   Acid Mine Drainage (AMD) is a very pressing environmental issue in today’s society; Colorado is particularly impacted by the presence of AMD. AMD impacts watersheds by lowering the pH and reducing the alkalinity of natural waters.  Using samples collected at the Captain Jack Superfund Site (an AMD site where the Big Five Tunnel drains into Left Hand Creek) we measured the alkalinity in the drainage from the Big Five Tunnel as well as above and below the confluence […]

Vapor Pressure of a Pure Liquid

Abstract: The enthalpy of vaporization, entropy of vaporization at 298 degrees Kelvin, and the compressibility factor of Heptane were determined by measuring the vapor pressure of the liquid at varying temperatures.  The enthalpy of vaporization was 26.77 ± 0.52 (kJ/mol). The entropy of vaporization at 298 K was 89.8 ± 1.7 (J/K mol). The compressibility factor was 1.31. The literature value for the enthalpy of vaporization was 35.07 (kJ/mol). The literature value for the entropy of vaporization at 298 K […]

BROMINATION OF TRANS – STILBENE

AIM:         The aim of this experiment is to carry out an addition reaction using trans-stilbene and bromine reagent to produce 1,2-dibromo-1,2-diphenylethane. As most chemicals used in this experiment are toxic / harmful, PPE must be used throughout and the experiment should be carried out inside a fume hood. THEORY: Bromine and chlorine readily undergo addition reactions with alkenes. This practical involves the bromination of trans-stilbene using a 10% bromine dichloromethane solution. Hence, an addition reaction takes place an 1,2-dibromo-1,2-diphenylethane […]

Preparing Standard Acid and Base

Abstract   Via acid/base titration with a primary standard (potassium hydrogen phthalate) an NaOH solution of unknown concentration was standardized. Once the NaOH solution was standardized, it was used as to determine the concentration of a KHP solution of unknown molarity.  In both instances, an acid/base indicator was used to signal the endpoint. Using the recorded volumes from the titrations, the molarity of the known solutions, and the molar mass of the compounds in the solutions of known concentration, the […]

Reduction of trans-Cinnamaldehyde

By: Jane Huang, Stephanie Thomas and Vasthi Yanes   Chemical Reaction Equation   Reaction Table Introduction The purpose of this lab is to perform a reduction of trans-cinnamaldehyde. This process consists of 1) mixing trans-cinnamaldehyde with sodium borohydride and methanol, 2) employing rota-vap and the rinsing and removal of aqueous layers to purify mixture, 3) drying the precipitate via gravity filtration. The use of metal hydrides, such as sodium borohydride and lithium aluminum hydride, is the most commonly used out of […]

Calibrating Flow Meters and Exploring Reynolds Number Report

Introduction: Lab group three was asked to calibrate the rotameter and orifice meter. It was also requested of us to measure the range of Reynolds numbers able to be read in the CM3215 laboratory. The orifice meter is a section of pipe with a restriction that acts to create a pressure drop. As the fluid approaches the orifice, the pressure increases and then suddenly drops as a result of the velocity increase through the reduced cross sectional area. A rotameter […]