Identification of an Unknown Weak Acid
Analytical Chemistry Laboratory 319 Experiment 7: Identification of an Unknown Weak Acid Formal Report Bonnie LaPierre Drawer G-1 Lab Date: Thursday March 13, 2008 INTRODUCTION: One of the more common reactions seen in chemistry is the acid/base reaction. The most common result of an acid/base reaction is the formation of water and a salt. Such a reaction can be highly useful in the analysis of an unknown acid or base. By titrating the unknown analyte with a standard reagent, several characteristics of the unknown can be determined, as well as the identity of the analyte itself. One important aspect of an acid/base reaction is the pH of the solution. Since an acid/base reaction is often performed by titrating an acid with a basic solution (or vice versa), monitoring the pH during the titration shows how the acidity is changing as reagent is added. By recording these pH values during the course of the reaction, a titration curve can be generated; from this curve, several characteristics of the reaction can be determined such as equivalence point(s), pKa(s), and end point(s), etc. In this experiment, the objective was to identify an unknown weak acid. This was accomplished by titrating the unknown acid with a standardized base. Using a pH meter, the pH values were recorded as the volume of added base increased until the pH reached a specified limit of 11. From these
Synthesis of Benzocaine
Synthesis of Benzocaine A. Introduction/Aims: The aim of the current investigation is to investigate the acid-catalysed Fischer esterification mechanism underlying the synthesis of the anaesthetic benzocaine using p-aminobenzoic acid and ethanol in excess. The resulting synthesised compound was subject to IR and melting point analyses in order to determine the identity and indeed the purity of the obtained sample. Benzocaine exhibits two main components common to the anaesthetic family: (1) an aromatic system usually having directly attached an ester and (2) a one to four unit hydrocarbon chain. The ester group is essential in body detoxification of this substance due to enzymatic cleavage of the ester linkage. Other anaesthetics may also contain a tertiary amine functional group which translates into the compound being soluble in the body. B. Stoichiometric Equations: C. Reactant table: Reactant/product M.W. (g mol-1) Quantities used/obtained Moles used/obtained Mole ratio theoretical/actual 4-aminobenzoic acid 37.14 5.00 g 0.036 /1, limiting Ethanol 46.07 65 mL = 51.42 g .12 /31.1, in excess Sulfuric acid 98.08 5 mL = 9.15 g 0.093 Benzocaine 65.19 4.05 g 0.025 0.025/0.036 = 0.69 The limiting reagent of this reaction is p-aminobenzoic acid. Thus the theoretical yield of benzocaine is expected to be 0.036 mols as a 1:1 ratio exists between
Heat of Neutralization in a Calorimeter with Weak and Strong Electrolytes
Heat of Neutralization in a Calorimeter with Weak and Strong Electrolytes Erin Lab Performed: November 11th, 2008 Section 006 T.A: Teresa Introduction The purpose of this experiment is to find the concentration of the unknown HCl as a strong electrolyte to observe the enthalpy changes between strong and weak electrolytes. This is conducted by using a "coffee-cup" calorimeter and a series of solutions: HCl, HNO3, NaOH (all strong electrolytes) and Phenol (weak electrolyte). Both strong electrolytes and weak electrolytes are used in this lab. The difference between strong electrolytes and weak electrolytes is that strong electrolytes completely ionize in aqueous solution making the solution a good conductor. In contrast, weak electrolytes do not behave the same way and will only partially ionize, but is only a fairly good conductor of electricity (Petrucci et al, 2007). The examples of strong electrolytes in this experiment are HCl, HNO3 and NaOH. The phenol solution that it is use is a weak electrolyte. The reaction is happening within a "coffee-cup" or Styrofoam cup calorimeter where the neutralization reaction between the NaOH and the acid will act as the system. The heat that is absorbed or released by the system during the reaction within the calorimeter, is called the heat of the reaction, q. The formula for q is: q = mc?t The heat of the system is comes from
Heat of Neutralization
Introduction The study of energy is an important component chemists use to study chemistry. Most of the energy used in society comes from chemical reactions, which include the combustion of fossil fuels. Another example of the practical uses of this theory is when gasoline is combusted in a car engine, the engine block becomes hot and the car's pistons move (Brain, 2007). This example demonstrates two ways heat can be transferred, which are through heat(temperature change) or work. Since a significant amount of work is not produced in chemical reactions, most of the energy comes in the form of heat (Jones, 2007). This component of chemistry is known as thermochemistry (Jones, 2007). During a chemical reaction, chemical bonds are created and destroyed, which means energy can be either released or absorbed. With constant pressure, the change in energy of a reaction is known as the heat of reaction or enthalpy change (?H) (Jones, 2007). In order to determine the amount of energy release or absorbed, chemists carry out the reactions inside a container, known as a calorimeter, that helps insulates the reaction from its surrounding (University of Florida, 2007). Therefore, all of the enthalpy change of a reaction is confined to the container, raising or lowering the temperature of its contents (University of Florida, 2007). This, in short, is the basis of calorimetry. However, for
Photochemical smog's comprise of primary and secondary pollutants.
Open book: 2003 Photochemical smog's comprise of primary and secondary pollutants. Primary pollutants are released directly into the atmosphere, through combustion of fuels in car engines and power stations. The main primary pollutants produced because of motor vehicle combustion are; Nitrogen oxides, carbon monoxide and various hydrocarbons. Secondary pollutants are produced by a further chemical reactions taking place with primary pollutants. Secondary pollutants comprise of O3, NO2, H2O2, HNO3, partially oxidised VOC's and PAN peroxyacetyl nitrate. (Illustrated below in figure 1.1) Formation of the ozone (secondary pollutant) summarised in figure 1.2 Coal is a fossil fuel (made from the decomposition of living material). All living organisms contain sulphur and therefore when coal burns, the sulphur compounds are oxidised to form sulphur oxides. Organisms store nitrogen as protein and therefore it is present in the coal, therefore when coal is burnt the nitrogen compounds are oxidised to form NOx. Also because of the high temperature of combustion the nitrogen and oxygen in the atmosphere combine to form thermal NOx. CO2 is a waste product of most combustion reactions, as the carbon in the organic material in the decomposed organisms oxidises it may partially oxidise to form carbon monoxide (summarised in figure 1.3) The best conditions for photochemical smog
Innovative Methods of Hydrogen Storage for use as fossil fuel replacement.
INNOVATIVE METHODS OF HYDROGEN STORAGE FOR USE AS FOSSIL FUEL REPLACEMENT August 13, 2001 Fossil fuels have been the fuel sources of choice for modern civilization. There are limited stores of these fuels, and man must go to increasing lengths to extract available stores. This has had adverse effects on the environment, and environmentalists are increasingly successful in their efforts to preserve areas that contain these reserves of fossil fuels. The United States depends on oil for over 50% of its energy needs. The finite supply of this energy source is escalating the search for alternative energy sources. Also, the combustion products of these fuels contribute to air pollution and global warming, further threatening the quality of life for all. Nuclear power generation was once thought to be the power source of the future. However, accidents at nuclear power facilities and disposal problems with the products of energy generation using this method have resulted in the rethinking of this energy source. Electric vehicles have been touted as the next step to eliminate reliance on fossil fuels. The stumbling block on this path is efficient and lightweight storage of enough power to parallel fossil fuel vehicles already in use. To date, there has been no storage system that can produce enough power to economically and safely power a vehicle for realistic use.
An Investigation into the Concentration of Commercial Bleaches
An Investigation into the Concentration of Commercial Bleaches Abstract: An experiment into finding out the concentration of four different samples of bleach was carried out. This involved doing a titration experiment in order to found out the unknown concentrations of the bleaches and to place them in order of 'value for money'. Sample A was found to have the highest concentration of hypochlorite, so one can assume that this sample would have the highest 'value for money'. Sample B had the lowest concentration of hypochlorite and could be presumed as having the lowest 'value for money'. Introduction: Titration is a type of experiment that is used to find the concentrations of unknown solutions. An indicator is usually used to tell whether or not the solution has changed colour. Once the solution has changed colour this is known as the end point1. Once the end point has been reached, the titration is finished and from here the concentration of the unknown solution can be worked out by using the titre (cm3) gained as guidance. In this experiment, it will focus on finding out the unknown concentration of four bleach samples labelled A, B, C and D. Each of the bleach samples contains sodium hydrochlorite (NaOCl). Starch will be used as in indicator for this experiment too. Safety and Equipment: Lab coat, safety goggles and plastic gloves were worn at all times during the
Add vector symbols
Andy Somody 97300-6222 ENSC 495 Assignment 1 Add vector symbols ). By definition, a normal vector to a plane is any vector which begins at a point on the plane and has a direction that is perpendicular (or orthogonal) to the surface of the plane. Both the (100) and (111) planes are defined in terms of their normal vectors. The (100) plane has a normal vector of [100], while the (111) plane has a normal vector of [111]. The angle that the sides of the pyramid shaped pit make with respect to the starting wafer surface can be represented as the angle between the (100) and (111) planes. The intersection between the (100) and (111) planes is displayed in the following diagram. Therefore, the angle between the (100) and (111) planes can be resolved by determining the angle between the [100] and [111] normal vectors. By the dot product property of linear algebra, we know that the dot product of two vectors A and B can be represented by the following equation: where |a| is the magnitude of vector A, |b| is the magnitude of vector B, and ? is the angle between the vectors A and B. We can also represent the three dimensional components of vectors A and B in the following manner: where x1, y1, z1, x2, y2, and z2 are scalar numbers that can take on any value. The magnitudes of the vectors A and B can be represented in the following manner: By the dot product property of linear
Perform a preliminary design evaluation for a plant to produce 30,000 te/yr of Maleic Anhydride (MA), C4H2O3, from a liquid feedstock containing 95% n-butane.
CET PART IIA EXERCISE 6 Process Synthesis 25th February 2003 Introduction The objective of the exercise is to perform a preliminary design evaluation for a plant to produce 30,000 te/yr of Maleic Anhydride (MA), C4H2O3, from a liquid feedstock containing 95% n-butane. The remaining 5% of the feed is iso-butane, which is taken to form carbon dioxide instantaneously under the reactor conditions. The reactor must be kept above 100 ºC everywhere to prevent condensation on the catalyst. The reactor operates around 400 ºC and 2.5 bara. Reaction Scheme The following reactions will take place in the reactor: C4H10 + 3.5O2 ? C4H2O3 + 4H2O C4H10 + 6.5O2 ? 4CO2 + 5H2O The selectivity of generating Maleic Anhydride, is given by S = 0.70 - 0.3X2 [1] where X is the conversion of n-butane Figure 1 below shows the distribution of products. Figure 1: Diagram showing distribution of products Using the information in Figure 1, the required flowrate of n-butane in the feed can be found, together with the compositions and flowrates of the product stream. The minimum air flowrate is defined by the fact that the concentration of n-butane in air must be below its lower explosion limit of 1.7 mol %. Basic Flowsheet The basic flowsheet to be considered is as follows: Figure 2: Basic Flowsheet Design Equation [1] shows that selectivity decreases with conversion, which
The Synthesis and Optical Resolution of Co(en)33+ isomers
The Synthesis and Optical Resolution of Co(en)33+ isomers. Kimberlee London Department of Chemistry, Saint John's University, Jamaica, NY Dr. Rosso Lab Date: March 1 and March 8, 2011 Report Due: March 22, 2011. Abstract: The tris(ethylenediamine)cobalt ion is an optically active compound. The enantiomers can be separated and disguised from each. This is done first through the synthesis of [(+)-Co(en)3[(+)-tart]Cl and then the debased from this complex. The separation results with [(+)Co(en)3]I3 and (-)-Co(en)3]I3. The two are disguised from each other by using a polarimeter and obtaining the optical angle of rotation. From this further calculations are done to further identify and determine if the enantiomers were separated and isolated synthetically. The results found that the isomers were separated and a great deal was recovered according to the theoretical yield that was calculated. It was also proven that the complex can be racemized by boiling and the presence of an activated carbon. Introduction: The purpose of this experiment is to synthesis and learn about Co(en)33+ optical isomers. The tris(ethylenediamine)cobalt ion is an optically active compound. Werner in 1912 was the first to do the resolution of tris(ethylenediamine)cobalt ion.1 He did this through Second-order Asymmetric Induction. Second-order Asymmetric Induction is when one of the
