CHEMISTRY 104 chem 2 lab 3 study guide

Nicole Surman Experiment 3: Titrations and Titration Analyses Title: Titrations and Titration Analyses Purpose: The purpose of this lab is to analyze Neutralization titrations, titrations between an acid and a base. Procedures: The following titrations were conducted in this experiment; strong acid/strong base, weak acid/strong base and strong acid/weak base. In order to perform a titration, a known and unknown material must be present. Determine M of sodium hydroxide by titrating against a weak acid, potassium hydrogen phythalate by adding in different indicators. Standardization titration #1 of NaOH: A strong acid/weak base were used in this titration. Phenolphthalein indicator was added to the solution of NaOH in a beaker along with water. The solution changed from colorless to a permanent pink color by adding the indicator with a buret. The endpoint is reached when the color pink remains permanent. Standardization titration #2 of HCl: Bromthymol Blue was added to the solution of HCl. A strong acid and strong base were used in this titration. We will try to standardize the solution using NaOH from the previous titration. The endpoint is reached when the color remains blue from yellow with a pH 6.0-7.6 Standardization titration #3 of vinegar: Weak acid vinegar which contains acetic acid mixed with the strong base of NaOH. Phenolphthalein indicator was added to the solution of 3.09g of vinegar to make a permanent pink color change with pH 8.0-9.6. We will try to determined % acetic acid in vinegar. Standardization titration #4 of ammonia: A beaker is placed on a balance which ammonia drops were added. Methyl orange indicator is added to HCl. A color change from yellow to orange would indicate a pH of 3.1-4.4. Standardization titration #5 of Antacid tablets: Antacid tablets were ground up into a powder in order to titrate with HCl into a flask. A pipet was used to add 25ml of 0.106 M HCl to flask. The flask was then placed into boiling water to burn off any carbonic acid. Bromphenol Blue was added as the indicator to reach a blue endpoint with pH at 3.0-4.6. We will then back-titrate. Standardization titration using pH meter: 35.0 ml of NaOH 0.107M was added to 25 ml of 0.108 M HC2H3O2 of 0.5-1 ml to reach a Phenolphthalein color change of pH 8.0-9.6. Data, Calculations, Results and Conclusion: Standardization titration NaOH: #1: 19.2 mL of NaOH was added to the solution to reach the endpoint Mass of KHC8H4O4: 0.51g Volume of NaOH: 19.2 ml This study source was downloaded by from CourseH on :25:05 GMT -06:00 MW= 204.22 NaOH Molarity: 0.51g / 204.2 g/mole / 19.2ml/1000 ml/liter= 0.130M Standardization of HCl: 21.9mL of NaOH was added to reach the endpoint Volume of HCl: 25.00 ml Volume of NaOH: 21.9 ml and 0.130M MHCl x 25.00 ml/1000 x 1/1= 0.130 x 21.9ml/1000 = 0.114M Standardization acetic acid in Vinegar: 19.7 mL of NaOH to reach endpoint. Mass of vinegar: 3.09g Volume of NaOH; 19.7 ml and 0.130 M MW= 60.052 %HC2H3O2= 19.7/1000 x 0.130 x 60.052 x 100/ 3.09= 4.95% Standardization of ammonia: 2.0693g of Ammonia 25.2ml of 0.106 M HCl to titrate solution and reach endpoint. Mass of ammonia: 2.0693g Volume of HCL: 25.2ml and 0.106M MW= 17.034 % ammonia in household ammonia: = 25.2/1000 x 0.106 x 17.034 x 100/ 2.0693= 2.20% Standardization of Antacid tablets: .2148 g of antacid 3.9mL of 0.107 M NaoH to reach endpoint. Mass of antacid: 0.2148g MW= 100.09 Volume of HCl: 25.00 ml and 0.106M Volume of NaOH: 3.9ml and 0.107M Excess HCl added: 0.106 x 25.00ml / 1000= 0.00265 Moles of base= 0.107 x 3.9 ml /1000= 0. This study source was downloaded by from CourseH on :25:05 GMT -06:00 HCl to neutralize CaCO3= 0.0026