In redox reaction, one element or compound is reduced and gains electrons, while on the other hand, the other element or compound is oxidized and loses electrons. For this lab, through the given oxidation and reduction numbers from balancing the equation and the electrons, it was shown that Manganese was reduced while Iron was oxidized. Also from the equation, the movement of electrons can be noticed, as it was added or subtracted from the substances. In order to balance an equation, there must be same number of elements on both sides, with the exception of hydrogen and oxygen. From there, in order to balance oxygen, water molecules are enumerated to the opposite of the equation/reaction.
As for endothermic the reactions pulls in energy and makes it cold to touch. The other experiment measured the pH level in the reaction. The reaction consisted of sodium hydroxide and hydrochloric acid also to see at which point the reaction becomes neutralized. Neutralization is a reaction between an acid and a base forming a salt and water even tho you can’t see the salt due to the salt dissolving into the solution and the pH level of the reaction around level 7 and has a green sometimes yellow colour when the universal indicator is added. The neutralization gap shows how small the gap is to make the reaction neutral.
Determination of Freezing Point and Verification of Freezing Point Depression for a Mixture by Linah Richer Partners: Maike Blakely CHM317 Preformed: Nov. 8th, 2013 Report: Nov. 19th, 2013 Abstract: The purpose of this experiment is to determine the freezing point of the solvent, biphenyl, and verify the freezing point depression equation ΔTf=-ikfnsolutemsolvent. The addition of solute will lower the vapor pressure of the solvent/solute mixture resulting in the lowering of the freezing point for the mixture solution. The experiment resulted in the experimental difference in the two trial freezing points to be 0.08 K leading to a calculated change in temperature freezing to be -1.92 E -5 K, and an overall decrease in temperature freezing of the solute/solvent solution compared to the pure solvent solution. Introduction: Experimentally it is understood that the addition of a nonvolatile solute to a solvent will lower the vapor pressure, raise the boiling point and lower the freezing point. In this experiment, the freezing point for the solvent biphenyl will be determined theoretically and experimentally, as well as the verification of the freezing point depression equation for a solvent/solute mixture.
In solutions that are more acidic than pH 3.2, it is protonated to form a red dipolar ion. Thus, methyl orange can be used as an indicator for titrations that have end point in the pH 3.2- 4.4 region. The indicator is usually prepated as a0.01% solution in water. In higher concentrations in basic solution, of course, methyl orange appears orange. Acid-Base Indicator Properties of Methyl Orange [pic] Procedure Pretreatment before Diazotization 1.
A pH indicator is a halochromic chemical compound that is added in small amounts to a solution so that the pH (acidity or basicity) of the solution can be determined visually. Hence a pH indicator is a chemical detector for hydronium ions (H3O+) or hydrogen ions (H+) in the Arrhenius model. Normally, the indicator causes the color of the solution to change depending on the pH. At 25° Celsius, considered the standard temperature, the pH value of a neutral solution is 7.0. Solutions with a pH value below 7.0 are considered acidic, whereas solutions with pH value above 7.0 are basic.
Methlyene chloride was a good solvent in this case because its boiling point is 40 degrees C and will boil off before the trimyristin which has a boiling point of 56-57 degrees C. Finally acetone was added to wash the crystals and the solution was vacuum filtered. This process was repeated and the trimyristin was collected. Results: Experimental yield of trimyristin= .64g Experimental melting point of trimyristin= 59 degrees C Percentage yield = experimental-truex100 True Dicussion: The extraction of trimystrin left white crystals resembling a powder. Its melting point was 56 degrees C which was exactly the recorded value. However, given that
This is called the shaking and venting procedure. This procedure allows the benzoic acid (benzoic is the solute) to establish an equilibrium between the two layers the organic layer and the aqueous layer. Benzoic acid, although it has dissolve in water, is not very soluble in water (it will only dissolve in water at elevated temperature). However, benzoic acid is more soluble in methylene chloride. That is why once you add the benzoic acid aqueous solution and the CH2Cl2 in the separatory funnel the benzoic acid moves from the aqueous layer into the methylene chloride organic layer.
TITRATION OF AN ACID (A PREPARED STANDARD SOLUTION OF KH₅O₄C₈) AGAINST A BASE (NAOH) USING PHENOLPHTHALEIN AS AN INDICATOR BY GRACE The aim of this experiment is to prepare a standard solution of potassium hydrogen phthalate (KH₅O₄C₈) and then use it to calculate the concentration of sodium hydroxide by titrating the acid (KH₅O₄C₈) against the base (NaOH). Before the whole experiment could take place, some apparatus were needed which included the following; A weighing balance, burette, pipette, a conical flask, clamp and then the setup was as below; THEORY To calculate for the moles of KH₅O₄C₈, I used n (mol) =m (g)/M (gmol⁻ⁱ (JOHN GREEN AND SADRU DAMJI, PG 6 OF CHAPTER 1.THIRD EDITION). Whereby m=mass of the acid, M=molar mass of the acid and n=number of moles. Molar mass of KH₅O₄C₈ is 204.1g/mol and its mass is 1g Therefore=1g/204.1gmol⁻ⁱ n=0.0048996mol Further more, to calculate for the concentration of the acid, I used C(moldm⁻3.) =n (mol)/v (dm3) Whereby c=concentration, n=number of moles and v=volume used.
It is very important to understand solutions, acids, and bases. The purpose of this experiment was to test the buffering ability of 4 substances. These consisted of water, milk, NaCl, and phosphate and were measured on the pH scale. PH is a measure of acidity or basicity, pH less than seven is acidic and solutions with a pH higher than seven are basic. An acid is a chemical compound that dissociates in a solution and releases hydrogen ions which lowers the pH.
The peroxide value (PV) test, which is one of the most common tests used to evaluate the extent of lipid oxidation, is based on measuring peroxides. Objective: To measure the PV or a number of food samples, and to evaluate the meaning of the results. Reagents: Acetic acid (glacial) Chloroform (CCl4) 15% Potassium iodide (KI) 0.01 N (0.01M) sodium thiosulfate (Na2S2O3) Starch indicator 0.5 % concentrated hydrochloric acid HCl 0.01 N (0.00167M) potassium dichromate K2Cr2O7 (fix.) Procedure Determination of the titre of the sodium thiosulfate solution Measure off 10 ml of 0.01N K2Cr2O7 solution to a 200 ml conical flask. Add 0.5 ml concentrated HCl and 1.0 ml 15% KI solution.