Observations of Chemical Changes Purpose: To examine the reactions of chemicals and see what types of changes can occur. Procedure: I used a 96-well plate and the following chemicals to document the chemical changes that occur: Ammonia, Bromthymol Blue, Copper (II) Sulfate, FDC Blue dye #-1, Hydrochloric Acid, Lead (II) Nitrate, Phenolphthalein Solution, Silver Nitrate, Sodium Bicarbonate, Sodium Hydroxide, Sodium Hypochlorite, and Starch Solution. Data Tables: Well #/Question | Chemicals | Reaction | A | NaHCO3 and HCl – CO2 | Bubbles formed | B | HCl and BTB | Turns a yellow/orange color | C | NH3 and BTB | Turned to orange | D | HCl and Blue Dye | Turns green | E | Blue Dye and NaOCL | Stayed blue | F | Kl and Pb(NO3)2 |
Radu Purtuc | Chemistry 231 - Lab | Section 32 Ronnie :: team-member TECH 705, SEPARATING ACIDS AND NEUTRAL COMPOUNDS BY SOLVENT EXTRACTION - MACROSCALE EXTRACTION July 6, 2006 Lab Report INTRODUCTION Purpose: using extraction technique to separate acetanilide, p-toluic acid, and p-tert-butylphenol; then measure the melting points of each compound and comparing them to the statistical values. Background: separating acids and neutral compounds by solvent extraction is a useful technique used in practice by chemists to separate organic compounds from mixture of other compounds. It generally involve several steps, with limiting factors being the number and output purity of compounds to be extracted from source mixture. A number of specific compound solvents not inter-miscible are used to separate and dissolve compounds, and a physical transfer between solvents is employed. An example of use is cleaning compounds of impurities, where different solvents work as a molecular filter that interacts differentially with compound and impurities respectively.
Esterfication Abstract: Through the process of esterification, carboxylic acid was reacted with an alcohol in order to produce an ester and water as the products. An acid called benzoic acid was reacted with an alcohol identified as ethanol. Through the use of heat and a catalyst, which in this case was sulphuric acid, an ester in the form of ethyl benzoate was produced along with water. The cherry odour comes from the ester called ethyl benzoate. Theory: The purpose of this lab is to achieve a specific odour through the process of esterification where carboxylic acid and alcohol react to produce an ester and water with the assistance of heat and a catalyst such as sulphuric acid.
However, from the GC the area % (also known as percent purity) was 91.8%, which indicates that a very pure product was obtained. REACTION MECHANISM OBSERVATIONS Please refer to page 36 and 37 of the lab notebook for a full list of observations and data RESULTS AND DISCUSSION a) Yield Calculations Theoretical Yield:3.5mL chlorpropane × 0.8669
To perform this experiment, we will utilize emission spectra, titrations, and thermal gravimetric analysis, using knowledge from Experiments 10, 4, Titrations of Na2CO3 and NAHCO3 by HCl (hydrochloric acid) will be performed to determine the concentration of HCl, as well as the number of moles of HCl present within the sample of baking soda. As a result, we will be able to determine the molar concentration of HCl by determining its equivalence point (the point on the graph where the exact amount of rectant needed to perform a reaction has been added) from graphical analysis. Na2CO3(aq.) + HCl(aq.) ==> NaHCO3(aq.)
It was important to know what vinegar was made up of to fine the percent composition when continuing on with the second investigation of this laboratory. A process called titration must be performed, before calculating the percent composition of acetic acid in vinegar. Titration is a strategy that helps in determining the exact quantity of the reactant in the titration flask and the exact endpoint of a reaction. To deliver the second reactant to the flask a buret is used. To note the endpoint of the reaction, a pH electrode probe is placed in the reactant.
This particular reaction is a strong acid and a strong base which means that when the reaction reaches the equivalence point, the moles of the acid and the base are equal and the solution is neutral so the pH should be around 7.0 depending on the final volume of each solution. To get this data, we will titrate an HCl solution with NaOH solution of which is a known concentration. We will record the initial and final reading of the NaOH while we record the pH of the titrated solution in the beaker. We will repeat this process with a solution of acetic acid which is a weak acid with NaOH and record the initial and final reading of NaOH and the pH of the solution in the beaker. Procedure Preview Calibrate the pH meter.
This is because when an azeotrope is boiled, the resulting vapour has the same ratio of constituents as the original mixture of liquids. Each azeotrope has a characteristic boiling point. The boiling point of an azeotrope is either less than the boiling points of any of its constituents (a positive azeotrope), or greater than the boiling point of any of its constituents (a negative azeotrope). The azeotropes of cyclohexanol/water and cyclohexene/water are both positive azeotropes. The separation of cyclohexene could not depend on distillation alone.
Riya Singh Banita Sathpathy Period 1 Analysis of a Commercial Bleach Purpose The purpose of this experiment is to determine the amount of sodium hypochlorite in commercial bleach by reacting the bleach with sodium thiosulfate. Procedure In this experiment a solution of sodium thiosulfate of known concentration will be added to the bleach using a buret in a titration procedure. The disappearance of the dark blue color of the starch- iodine complex will signal the end point. Data Trial 1 Trial 2 Trial 3 Initial Reading (ml) 0 0 0 Final Reading (ml) 35.7 36.0 36.6 Volume of Na2S2O3 35.7 ml 36.0 ml 36.6 ml Calculations and Analysis 2 S2O3-2 = I3- = I2 = ClO- Therefore looking at the equation above, we can conclude that for every mole of sodium thiosulfate we need half a mole of sodium hypochlorite. (35.7+36+36.6)/3=36.1 ml is the average volume of the Na2S2O3.
Title: Bromination of (E) – Stilbene (Microscale Procedure) Author’s Name: Reinaldo George Professor: Elvis Barrett Date of Experiment: Thursday July 16th 2015 Institution: Nova Southeastern University Abstract The purpose of this experiment was to synthesize the second intermediate in the b series of Sequential Reactions by carrying out the bromination of (E)-stilbene to obtain meso-stilbene dibromide. This product is the precursor to diphenylacetylene, the next synthetic intermediate in the b series. A further purpose of this experiment is to demonstrate the stereospecific addition of bromine to alkenes. The percentage recovery was also calculated and recorded. On completion of this experiment; my lab partners and I were able to successfully synthesize the second intermediate in the b series of the