Mole ratio is considered a conversion factor since it helps to convert units with the use of moles. It is used in stoichiometry and other calculations and comes out of the balanced chemical equations. Stoichiometry is the measurement of elements that concerns the chemical quantities produced or taken in a reaction. The process of relating the mass and mole quantities of reactants or products in a reaction. It uses a balanced chemical equation, mole ratio, and sometimes needs mole mass.
Purpose: The purpose of this lab is to titrate an unknown solid acid (KH2PO4) with a standardized sodium hydroxide solution. After recording and plotting the data, the acid’s equivalence point will be recorded once the color changes. Using the equivalence point, the halfway point will be calculated, which is used to determine the acid’s equilibrium constant. The acid’s calculated equilibrium constant will be compared with the acid’s established pKa value. Eventually using the NaOH and the acid’s consumed moles, the equivalent mass will be determined.
In the sodium iodide test, the alkyl halide is added to sodium iodide in acetone. In this test, primary halides precipitate the fastest while secondary halides need to be heated in order for a reaction to occur. Comparison of the rates of precipitation of the obtained product to standard 1° and 2° bromide solutions will show whether the product is a primary or secondary
When an aromatic compound such as phenol undergoes nitration, it does so through an Electrophilic Aromatic Substitution (EAS). Undergoing this reaction requires two steps. The first step is the addition of the electrophile, which in this lab was the Nitronium ion formed by the dilute nitric acid solution. This is the rate determining step for this reaction, as during this step aromaticity is lost and the arenium ion is formed. The position of the electrophile to be added is determined by how well the arenium ion can be stabilized once the initial addition occurs.
The purpose of the K_a determination of an unknown weak acid lab was to use titration in order to determine the K_a for an unknown solid weak acid knowing only its molar mass. The previous laboratory experiment was performed in order to determine whether titration or dilution would yield more accurate K_a. It was determined that titration yielded more accurate results. This lab was performed by taking a sample of solid weak acid and dissolving it in water before titrating with the strong base NaOH. Titration is a technique in which a reagent of known concentration is slowly added to an unknown solution in order to calculate the concentration of the unknown.
The chromatogram confirmed the identity of the lower boiling point solvent as acetone, and the higher boiling point solvent as toluene. The unknowns were correctly identified due to the clear presence of two plateaus in the experimental data. The hot plate was not turned on too high or too low to not obtain one of the three samples, and a sufficient number of values were taken in each part of the distillation before the mixture evaporated away to obtain approximately accurate data for boiling points. The ratio calculated for the volume of solvents in the mixture was .506/.488, where the composition of the mixture was 50.6% acetone, and 48.8% toluene. These two values did not add up to 100% because the GC also recorded some impurities,
In general, these substances can be divided into short-acting products (procaine), intermediate-acting (lidocaine, mepivacaine) and long-acting (bupivacaine, ropivacaine). The inhibitory effect first reached the fibers of the autonomic nervous system and fibers sensitive to pain, cold, warm to the touch, and finally the motor fibers; and conversely when the action of the anesthetic disappears. This stopping of the peripheral nerve transmission is from an inhibition of the excitation potential due to a blocking of the opening of the sodium
These two positive test allowed for a GC spectrum to be obtained, if the IR confirmed there was no water in the final compound. The IR spectrum obtained, did contain a peak at 3388 cm-1, indicating an alcohol group present, but the degree of the peak was so small that a GC spectrum could be obtained. This peak could have represented water present in the solution, but its presence was so low that it would not affect the
This would have made the results less accurate and made any errors change the final results even more. To make sure this doesn’t happen, there needs to be more trials to increase the precision of the results. Abstract The purpose of the lab was to determine what each of nice substances was based upon how they reacted with other chemicals as well as their pH levels. By using the given clues, the reaction with Litmus paper, and the precipitates formed by different mixtures, the chemicals were identified. Substance 1 was found to be BaCl , substance 2 was determined to be NaOH, and substance 3 was labeled as CuSO .
Introduction: The acid-base titration experiment is the use of a titrant, an analyte, and an indicator. Titration is the slow addition of one solution of a known concentration (called a titrant) to a known volume of another solution of unknown concentration until the reaction reaches neutralization, which is often indicated by a color change.1 The titrate is what is later released into a beaker or flask that is filled with the analyte and indicator. The color change happens because of the indicator. The correct shade of light pink will show when it has reached the equivalence point. Common places that use this experiment are pharmacies and doctor offices.