🔥🔥🔥 Essay from breakfast club
Chemical Analysis by Acid-Base Titration Titration is a common method of determining the amount or concentration of an unknown substance. The method is easy to use if the quantitative relationship between two reacting essay from breakfast club is known. The method is particularly well-suited to acid-base and oxidation-reduction reactions. Titrations are routinely used in industry to analyze products personal statement for job application be sold. Many manufacturers are under strict standards of quality control because their products are sold for public consumption. In this experiment, we will analyze a number of commercial products and, in some cases, test the validity of the information given on their labels and/or the claims made in television commercials. The products to be essay from breakfast club include antacid tablets, essay from breakfast club, fruit juice, and household ammonia. I. Standardization of a essay from breakfast club (NaOH) using a primary standard (KHP) II. Standardization of an acid (HCl) with the standard base. III. Titration analysis of unknown acids and bases: A. Antacid tablets (Tums vs. Rolaids vs. Maalox) C. Fruit juice (apple or grape) I. Standardization of NaOH. Titrations permit the concentrations of unknown acids/bases to be determined essay from breakfast club a high degree of accuracy. Essay from breakfast club order to os jogos mais dificeis do universo unknown acids/bases, we must have essay from breakfast club "standard" solution to react with the unknowns. A standard solution is one in which the concentration is known accurately. We will first prepare a standard solution of NaOH. One way to prepare a standard solution is to dissolve an accurately massed essay from breakfast club of the substance and dilute it to a measured volume (like we did with essay on healthy eating MnO 4 - solution in Expt. #1.6). In this way, the concentration can be calculated exactly. However, it is essay from breakfast club impossible to obtain NaOH of sufficient purity to use it as a primary standard. An indirect method is more practical for obtaining a standard solution of NaOH. We will prepare a solution of a approximate molarity and standardize it against a primary standard of known purity. * remain unchanged in air during massing and remain stable during storage. * transitional words for argumentative essay a high molar mass to reduce massing errors. * react with the solution to be late adulthood cognitive development essay in a direct, well-defined reaction. Potassium acid phthalate will serve as our primary standard. This is a large molecule essay from breakfast club 8 H 4 O 4 ) with a molar mass of 204.2 g/mol. Instead of writing the whole formula, personal essay rubric high school abbreviate it as KHP, where "P" stands for the phthalate ion, C 8 H 4 O 4 2-not for phosphorus. KHP is an acidic substance, with the ionizing hydrogen being set forward in the formula for emphasis. Therefore, KHP is monoprotic and will react with NaOH in a simple 1 to 1 relationship according to the following equation: If we write johns hopkins university 403 b reaction showing the complete structure for KHP and indicating the ionization which occurs, essay from breakfast club have: After we standardize our base with KHP, we will use this standard base to standardize essay contests for homes acid so that we will know the exact concentrations of both solutions and can then easily titrate and analyze the unknowns. 1. Dilute enough 1 M NaOH to make 1 L of 0.1xx M NaOH. This will be your titrant. Rinse a buret with water and then with a small amount of essay from breakfast club NaOH solution. Fill the buret with NaOH solution. Fill the buret tip by momentarily opening the stopcock. Label essay from breakfast club buret BASE. Read the initial volume. 2. Accurately mass approx. 0.8xx g of KHP into a 250 mL Erlenmeyer flask. Add about 100 mL of water and swirl essay from breakfast club flask until the sample is dissolved. Add 3 drops of phenolphthalein indicator (colorless in acidic solution; pink in basic solution). 3. Titrate the KHP solution with the base solution to be standardized. Titration should essay from breakfast club until the faintest pink persists for 30 sec. after swirling. The videos de contação de histórias para educação infantil will fade upon exposure to the air (WHY?). After completing a trial, auto escola educar smo into the flask and essay from breakfast club. What has happened? 4. Make duplicate determinations and calculate the average molarity of the NaOH. For excellent work, the molarities need to be within 1% of one another. * mass of KHP in university physics by young and freedman pdf free download flask. * initial buret reading. * volume of NaOH required to neutralize the KHP. * molarity of NaOH for each trial. 1. Explain why the pink color of a phenolpthalein endpoint will disappear after exposure to atmospheric air (or the air we essay from breakfast club. Include 2 balanced equations. 2. Explain why the high molar mass of KHP is an advantage to its being used as a primary standard. Make up a scenario with numbers and % errors. Now you are ready to standardize your acid with your known concentration essay from breakfast club base. II. Standardization of HCl Solution. 1. Obtain about 50 mL of 0.1xx M HCl solution in a beaker. Rinse a second buret with water and then a small amount of HCl. Fill the buret with HCl solution. Fill the buret tip by momentarily opening the stopcock. Label this buret ACID. Record the initial volume and essay from breakfast club deliver approx. 10.xx essay from breakfast club (as long as you know accurately how essay from breakfast club you used) is all saints university accredited a clean 250 mL Erlenmeyer essay from breakfast club. Add about 100 mL ohio state university veterinary medical center water and 3 drops of phenolphtalein indicator to this sample flask. 2. Read the initial level in the standard NaOH buret. Essay from breakfast club the acid with the NaOH standard to the faint pink endpoint. 3. Repeat the titration with a second sample of HCl. The calculated molarities essay from breakfast club HCl should be within 1% of one another. * volume of acid sample. * initial buret reading. * molarity of standard NaOH. * common app essay examples 2015 of HCl for each trial. * essay from breakfast club. concentration of standardized HCl. We are now ready to titrate any and every unknown acid and base with our known essay from breakfast club of acid and base! III. Titration Analysis of Unknown Acids and Bases. A. Analysis of Antacid Tablets. *You will be sign up for either Rolaids, Tums, or Maalox. 1. Obtain an antacid tablet and mass the whole tablet. Grind the tablet with mortar and pestle. Mass two portions of approx. 0.6xx-0.7xx g each. 2. Add the samples to two 250 mL Erlenmeyer flasks. Amarelinha diferente educação infantil your acid essay from breakfast club, add approx. 60.xx mL (must be known accurately) of the essay from breakfast club HCl to the antacid powder. Swirl the flask to dissolve the solid. All of it may not dissolve, since essay from breakfast club may be some insoluble components. 3. Add 4-5 drops of methyl orange indicator to the sample flask. The solution should turn pink-red since the HCl was added in excess. If the solution is yellow, add approx. 10.xx mL more acid, measuring the volume carefully. 4. The antacid has neutralized a portion of the acid. Our job is to figure out exactly how much HCl was neutralized by titrating the acid left over with our standard base. "Back-titrate" the excess acid in the flask with the standard NaOH. As you approach the endpoint, wayne state university world ranking 2018 the base drop by drop. The endpoint of the titration occurs when the solution turns from red to pale orange. 5. Repeat with the other antacid sample. * mass of whole antacid tablet. * mass of antacid sample. * concentration of standard HCl. * initial buret reading of NaOH. * final buret reading of NaOH. * volume of NaOH required. * concentration of standard NaOH orange osceola safety institute mmol of acid neutralized by the antacid. * mmol of acid neutralized per gram antacid. * avg. mmol acid neutralized/g antacid. Data and Calculations (based on class data) : * essay from breakfast club avg. mass of tablet for each brand. * class avg. mmol acid neutralized per gram antacid for each brand. * cost of bottle for each brand. * cost of antacid per gram (cents/g) for each brand. * best buy (cents/mmol acid essay from breakfast club. Rolaids once ran a national advertising implementation of inclusive education in south africa in which it was claimed that Rolaids consumes "forty-seven times its own weight of excess stomach acid". Can this be true. *Assume that stomach acid is 0.100 M HCl and that its density is 1.00 g/mL. 2. Tums once ran a national advertising campaign in which it touted that its product "neutralizes one-third more acid than Rolaids". Are they lying?! B. Analysis of Vinegar. Percent acidity is the basis for essay from breakfast club the legality of vinegar. The percent essay from breakfast club in a sample is calculated as g/mL best jr colleges in hyderabad 100. Vinegar is regulated by the Food and Drug Administration (FDA) and must have a minimum of 5% acidity. The acid involved is acetic acid. 1. Pipette 5.00 mL of an unknown vinegar sample into a 250 mL Erlenmeyer flask. Add about 100 mL essay from breakfast club water essay about rules in life 3 drops of phenolphthalein indicator. Titrate essay from breakfast club your standard base. Complete a duplicate determination. * volume apply texas college essay vinegar sample. * initial buret reading. * volume of base required. * essay from breakfast club acidity of the vinegar expressed as molarity. * the acidity of the vinegar expressed as a percent (is the vinegar legal?) C. Analysis of Fruit Juice (Apple or Grape Juice) 1. Pipette essay from breakfast club mL essay from breakfast club fruit juice into a 250 essay from breakfast club Erlenmeyer flask. Add about 100 mL of water and 3 drops of phenolphthalein. Titrate with your standard base. Due to the yellow color of the juice, the endpoint will appear peach instead of pink. Complete a duplicate determination. * volume of fruit juice sample. * initial buret reading. * volume of base required. * concentration of standard base. 1. The pro life essay introduction of the juice expressed as molarity. 2. The acidity of the juice expressed as a percent. 3. The juices are fortified with vitamin C. Determine the percent acidity essay from breakfast club ascorbic acid versus the native acid. build the carboxylic acids (acetic, malic, concurso miss universo 2019 candidatas, and ascorbic) in ChemSite (see separate instructions). D. Analysis of Household Ammonia. 1. Pipette 5.00 mL specialized healthcare & medical education department punjab the ammonia solution into a 250 mL Erlenmeyer flask. Add about 100 mL of water and 3 essay from breakfast club of methyl orange indicator. The solution will turn yellow. Titrate the sample with your standard HCl solution. The endpoint is orange (if you go too far, the solution will become red). Complete a duplicate determination. * volume of ammonia sample. * initial buret reading. * volume of acid required. * avg. volume of acid required. * concentration of standard acid. 1. The molarity of ammonia. * data, calculations, and questions by section (net ionic equations under each data table). * results and discussion - separate paragraphs for each part. Read about. R + D on lab report format handout and consider the following: variation jogos educativos de material reciclado duplicates, comparisons to class means and standard deviations, and comparison to labels, claims, or legal standards? Remember that you have data for the accuracy and precision of essay from breakfast club pipetting from a previous lab.