How it was expected the pH at equivalence point was 9.17 this is because of the domination of hydroxide ion in solution. The relationship between the pH and the amount of titrant added offered a better understanding of the equilibrium properties of the acid. Introduction Titrations are a convenient and common method of analysis. Generally titration is an experiment where a known property of one solution is used to infer an unknown property of another solution. There are several types of titrations: Acid-base titrations are based on the neutralization reaction between the analyte and an acidic or basic titrant.
The absorption spectrum is measured using a spectrophotometer and the data is graphed in Excel. The peak of the line is used to find Vmax of Fe2+. Vmax is used to find the moles of Fe2+ and ligand. The unknown n is a ratio of moles ligand divided by moles Fe2+. Results and Discussion For the first part of the experiment (Part A), five different 100 mL volumetric flasks were each filled with 1,2,3,4 and 5 mL of iron (II) solution.
Establishment of the Equilibrium Constant and pKa Experiment 14 Chemistry 112—Section: 532 Tanner Weyerts*—Primary Author Michael Vallon—Lab Partner Introduction This experiment involved taking bromothymol blue or the HBB indicator and gathering data on its relationship of absorbance. HBB’s reaction to the concentrations differs in blue, green, and yellow colors with respect to their basicity, neutrality, and acidity. Using the spectrophotometer, the percent transmittance is obtained and can be translated to determine the equilibrium constant and pKa. Materials and Methods Part One involved the preparation of samples for determining the percent transmittance using the spectrophotometer for Part Two. A cuvette block, four cuvettes, three 50 mL beakers, one 150 mL beaker, and one 5mL pipet were obtained.
Record several points of pH and NaOH added (especially near equivalence point) to be use later to prepare a titration curve. Observations and Results Part I: Solution | pH | 0.1 M HCl | .70 | 0.1 M NaOH | 13.30 | Part II: Volume of 0.1 M NaOH at equivalence point: 35mL pH at equivalence point: 11.45 Molarity of the Unknown Acid A (HCl): 2.0 x 10-4 Discussion In this lab, we found out that water self ionizes itself into hydrogen ion and hydroxide ion naturally to a very small extent. An indicator, in an acid base reaction, is a substance whose color changes over a particular pH range. Phenolphthalein is an example of an indicator which changes from colorless to pink as pH goes from 8 to 10. We plotted the pH against the amount of base added producing a
Chemical environment surrounding the carbons are different and therefore affecting the character of the hydrogens attached. This difference in chemical environment finally explains the different interaction between hydrogen and chlorine. Determination of percent yield, and relative reactivity data was processed after the products of the reaction were analyzed using Gas Chromatography. Percent yield was calculated for each isomer and determined to be; 5.94% for 1,1-dichlorobutane, 23.1% for 1,2-dichlorobutane, 47.1% for 1,3-dichlorobutane, and 23.9% for 1,4-dichlorobutane. The relative reactivity of the hydrogens H1, H2, H3 , and H4 were 0.37, 1.4, 2.9, and 1.0 respectively.
The reaction is a synthesis. The Kc for this reaction is Kc = 49.7 at 458oC [Answer: [H2] = [I2] = 1.2 × 10-2 M, [HI] = 8.6 × 10-2 M] 2. Iodine and bromine react to give iodine monobromide, IBr. What is the equilibrium composition of a mixture at 150oC that initially contained 0.0015 mol each of iodine and bromine in a 5.0 L vessel? The equilibrium constant Kc for this reaction at 150oC is 1.2 102.
CHM 238 TITLE: Luminol PURPOSE: The purpose of this experiment was to synthesize luminol (5-aminophthalhydrazide) from 3-nitrophthalic acid and observe the energy transfer to a fluorescent dye. As a big picture, the purpose of the experiment was to demonstrate how a chemical process can lead to a photochemical outcome though the synthesis of luminol. DISCUSSION: In part A of the experiment, 3-nitrophthalic acid reacted with hydrazine forming 5-nitrophthalhydrazide, a cyclic diamide. The solvent used in this reaction was triethylene glycol, which allowed for the dehydration of hydrazonium salt. The nitro group of 5-nitrophthalhydrazide was reduced with a mild reducing agent, sodium dithionite, in part B.
4. In test 1, which test tube showed signs of a change? Do you think it is a physical or chemical change? Why? The test tube that showed signs of change was the test tube that contained I2 & H, which turned dark red and had some strong odor and did dissolved.
ABSTRACT Isopropyltoluene isomers were synthesized through the friedel-crafts alkylation of toluene with 2-chloropropane in the presence of aluminum chloride as a catalyst. Through extraction of the distillate with water and 5% NaHCO3, followed by a fractional vacuum distillation, the desired aromatic organic compound was isolated. Infrared Spectroscopy and Gas Chromatography were used to analyze the composition, purity and to confirm the identity of the prepared product. The sample weighed approximately 2.66g, which reflected a low yield at 47%. However, from the GC the area % (also known as percent purity) was 91.8%, which indicates that a very pure product was obtained.
| Summary: Alcohols________________ | Water (highly Polar)_____ | Hexane (Non-Polar)______ | 1-OctanolCH3(CH2)6CH20H | Insoluble | Soluble | 1-ButanolCH3CH2CH2CH2OH | Partially soluble | Soluble | Methyl AlcoholCH3OH | Soluble | Insoluble | Part C: Miscible or Immiscible Pairs: In the experiment Part C we will obtain five test tubes total, four filled with water and the last test tube with Hexane. With the five test tubes we will be mixing other liquids in each individual test tube to see if the solution is miscible or immiscible. Note to take, like mixes with like. Procedure | Observation | TT1: 1ml water + 1ml Ethyl Alcohol | Miscible | TT2: 1ml water + 1ml Diethyl Ether | Immiscible | TT3: 1ml water + 1ml Methylene Chloride | Immiscible | TT4: 1ml water + 1ml Hexane | Immiscible | TT4: 1ml Hexane + 1ml Methylene Chloride | Miscible | Part D: Solubility of Organic Acids and