Experiment 2: Analysis of Commercial Bleach Solutions

Save this PDF as:
Size: px
Start display at page:

Download "Experiment 2: Analysis of Commercial Bleach Solutions"

Transcription

1 Experiment 2: Analysis of Commercial Bleach Solutions I. Introduction The ability of household bleach to remove stains is related to the amount of oxidizing agent in it. The oxidizing agent in bleach is sodium hypochlorite, NaOCl, which dissociates in water as follows: NaOCl (aq) Na + (aq) + OCl - (aq) (1) In this experiment we will determine, by titration, the % NaOCl in commercial bleach solutions. We will compare the concentration of sodium hypochlorite available in a name-brand vs a generic bleach. The method by which this will be accomplished is to first add an excess of potassium iodide, KI, to an acidified sample of diluted bleach. The following reaction will occur: OCl - (aq) + 2H + (aq) + 2I - (aq) I 2(aq) + Cl - (aq)+ H 2 O (l (2) The produced product, I 2(aq), is yellow when dilute and red-brown when concentrated. The amount of I 2(aq) formed by this reaction will then be measured by titrating it with a standardized solution of sodium thiosulfate, Na 2 S 2 O 3, which reacts with I 2 (aq) as follows: 2S 2 O 3 2- (aq) + I 2(aq) S 4 O 6 2- (aq) + 2I - (aq) (3) From the volume of standardized Na 2 S 2 O 3 solution used, the % NaOCl in the sample can be calculated. The instructions for this experiment are written in the traditional, compact form. This form does not include reminders to clean/zero the balance before use, or reminders to rinse pipet/buret first with deionized water, then with the solution to be measured. These are considered to be basic laboratory techniques, which you would know to do without being reminded. All Chem 401 experiments will be written this way. Primary Standards A primary standard is a material that can be quantitatively used to determine the concentration of other substances. In order to be a good primary standard, a substance must be a) of high purity b) stable c) no waters of hydration (not hydroscopic or hygroscopic) d) have a high molar mass e) be soluble in the solvent of interest. In this experiment, we need to know the concentration of the sodium thiosulfate very accurately, because it will be used to stoichiometrically determine the concentration of hypochlorite ion in our bleach. However, it forms a hydrate, with 5 waters of hydration. This means that it cannot be weighed out accurately as a primary standard. We must prepare it at an approximate concentration and then standardize it against a primary standard. The primary standard that we will be using is potassium iodate, KIO 3. Potassium iodate can be used to standardize the sodium thiosulfate by the following reactions. First, a known amount of KIO 3 (limited reactant) is reacted with an excess of KI in an acidified solution: IO 3 - (aq) + 5I - (aq) + 6H + (aq) 3I 2(aq) + 3H 2 O (aq) (4) Rev:

2 This produces a known amount of I 2 in solution. (You may be asking yourself, why didn t we just weigh out the right amount of iodine and dissolve it? The reason is that it cannot act as a primary standard either. Iodine is not stable enough. It sublimes at a fairly low temperature!) This known iodine concentration can then be titrated against the unknown (or only approximately known) thiosulfate concentration, based on the reaction: 2S 2 O 3 2- (aq) + I 2(aq) S 4 O 6 2- (aq) + 2I - (aq) (5) Note this is the same reaction as shown for the analysis of the bleach above (3). During the first half of the experiment, the concentration of the thiosulfate solution is the unknown that we are standardizing against a primary standard. Once its concentration is known, it becomes a secondary standard, which can be used to determine the concentration of an unknown concentration of iodine. This time the iodine will come from the reaction with the hypochlorite we are trying to determine. II. Experimental Procedures A. Equipment needed Set-up in lab: 25mL burette, funnel Chemicals in lab: Na 2 S 2 O 3 5H 2 O, KIO 3, KI, 1M HCl, 1% starch solution, name-brand (Clorox) bleach, generic bleach B. Waste Disposal Pour all titrated solutions and excess left-over reagents into the large bottles labeled "Used I -, S 4 O 2-6, Starch, Bleach Waste". C. Experimental considerations: 1. The concentrated bleach solutions can cause bleach spots if splashed on clothing. Be sure to use with caution and to keep goggles on at all times. You may want to wear a protective coat or apron during this experiment. D. Before Starting Experimental Work (Before Class) 1. In your notebook, enter the experiment title, date, your name and name of partner. Number each page in your entire notebook if you have not already done so. 2. Write the purposes of the lab. 3. Write out all reactions that are involved in the analysis. 4. Write an executive summary of the procedures described in this lab. Include all major procedural steps that you will need to follow. E. Procedure 1. Preparation and standardization of 0.05 M Na 2 S 2 O 3. a. To prepare the ~0.05M sodium thiosulfate solution: Add approximately 1.9 g of Na 2 S 2 O 3 5H 2 O into a large (250 or 500mL) beaker or Florence flask. Record the weight in your lab notebook. Add approximately 150 ml of deionized water (with your large graduated cylinder) and stir or swirl the mixture until the Na 2 S 2 O 3 5H 2 O has completely dissolved. Condition and fill a ml buret with the sodium thiosulfate solution. b. To prepare the potassium iodate (primary standard) solution: Accurately weigh out 0.24 g of KIO 3 (using the most sensitive balance available) into a weighing boat. Record the weight in your lab notebook. Transfer to a 100mL volumetric flask. Add enough deionized water to half fill it. Rev:

3 Swirl the mixture until the KIO 3 has completely dissolved. Carefully add more DI water until the bottom of the meniscus reaches the mark on the neck of the flask. Cap the flask and invert it with shaking times to insure complete mixing. c. Preparation of a solution of known iodine concentration: Pipet ml of the KIO 3 solution into a clean 125 ml or 250 ml Erlenmeyer flask. Add 30 ml deionized water and 0.5 g KI (about 1 small scoop). Swirl the mixture until the KI completely dissolves. Add 10 ml of 1 M HCl (using your small graduated cylinder) and swirl for 1 minute. A brownish red color will appear due to the presence of aqueous iodine. d. Standardization of the sodium thiosulfate (secondary standard) solution: While swirling the solution from step c, add the Na 2 S 2 O 3 solution from the buret until the brown fades to yellow. Add ~2mL of starch suspension (using your small graduated cylinder). The solution in the flask should turn dark blue because of a complex that starch forms with iodine. (You do not need to record the volume at which you added the starch!) Continue adding the Na 2 S 2 O 3 solution drop-wise with swirling until the dark blue color disappears. (A little blue adhered to the outside of the starch particles may still be present.) Record the total volume of Na 2 S 2 O 3 solution delivered (from the start of the titration to where the indicator color has disappeared) to 2 decimal places in Table 1. Pour this titrated solution into the large bottles labeled "Used I -, S 4 O 2-6, Starch, Bleach. Additional rinses do NOT need to go into the waste container. Repeat Steps c and d two more times, for a total of 3 titrations. If all volumes delivered agree within 0.2 ml, continue to Procedure 2. If not, show your results to your instructor. You may be required to perform a 4 th titration. F. Procedure 2. Titration of the Liquid Bleach a) To a clean 125 ml or 250 ml Erlenmeyer flask add 30mL deionized water and 0.5 g KI (about 1 small scoop). Swirl until the KI has dissolved. Add 10 ml 1M HCl using your small graduated cylinder and swirl to mix. Add 0.500mL of the name brand (e.g. Clorox) liquid bleach. Swirl for 30 seconds, and then titrate with the Na 2 S 2 O 3 solution until solution turns from red-brown to yellow. Add ~2mL starch suspension and titrate until the dark blue color disappears. (A little blue adhered to the outside of the starch particles may still be present.) b) Repeat this procedure with 1 more sample of the name-brand bleach. Average the results of your two titrations. c) Repeat steps a and b with a sample of generic bleach. d) Review your results with your instructor. If your titrant volumes vary too greatly for a given bleach, you may be asked to do one more titration if time permits. e) After your instructor has approved the values, pour the unused KIO 3, 1M HCl, and Na 2 S 2 O 3 solutions into the large plastic bottles labeled "Used I -, S 4 O 2-6, Starch, Bleach". f) When finished, rinse your buret several times with DI water, fill it with DI water, stopper it, and return it to its original location. Also refill your DI wash bottle for use in the next experiment. Rev:

4 III. Further Instructions A. Required Calculations 1. Q-test: The Q-test is a statistical test to evaluate potential outlier points in a data set. The calculations for the Q-test are explained in detail in the introduction to this lab manual. Apply the Q-test to see if any of the 3 or 4 volumes from your standardization of sodium thiosulfate (Procedure 1d/e) should be eliminated from the average volume calculation. Be sure to list the suspect value, calculated value of Q, the critical value of Q from the table, and your decision to accept or reject the suspect data point. 2. Determination of average volume of sodium thiosulfate solution used: Calculate the average volume of sodium thiosulfate used to titrate the 10.00mL portion of the potassium iodate primary standard. In determining the average, only use those values that the Q-test told you to retain. 3. Determination of the concentration of the sodium thiosulfate solution. Use the average volume of sodium thiosulfate to calculate the molarity of the Na 2 S 2 O 3 solution. Use the stoichiometry from the reactions shown in the introduction section. Be sure to use good dimensional analysis and show all of your units! 3a) First calculate the molar mass of KIO 3. 3b) Next calculate the molarity of the KIO 3 solution. 3c) Calculate the moles of KIO 3 (or IO 3 - ) in your 10.00mL aliquot. 3d) Use stoichiometric factors (from equations 4 & 5) to convert mole IO 3 - to mole S 2 O f) Calculate the molarity of the S 2 O 2-3 solution from the average titration volume determined in calculation Determination of the % NaOCl in the bleach: From the average volume of Na 2 S 2 O 3 used in Procedure 2, calculate the % NaOCl in each bleach solution. 4a) Calculate the mol S 2 O 2-3 used based on the average titration volume for the name-brand bleach from procedure 2, and the molarity of Na 2 S 2 O 3 from calculation 3. 4b) Calculate the mol of OCl - in the aliquot of name-brand bleach using stoichiometric factors from equations 3 & 2. 4c) Convert mol OCl - to g NaOCl using the molar mass of NaOCl. 4d) Determine % (mass/volume) bleach (NaOCl) in the name-brand bleach. (Remember this is the mass of solute in grams per ml of solution.) Record your result in Table 2. 4e) Repeat calculations 4a to 4d for the generic bleach. B. In-Class Work 1. All data collection must be completed during class time. 2. Perform calculations A1, A2 & A3. C. Results: at home 1. Complete all remaining calculations in Section A 2. Place a copy of the Q-table critical values (from the Lab Manual Introduction) inside the back cover of your laboratory notebook. Rev:

5 D. Discussion and Experimental Summary: In your notebook, after completion of all experimental work and calculations, create the heading Discussion and Experimental Summary. 1. What percent stronger (or weaker) was the name-brand bleach versus the generic bleach? % NaOCl in name brand bleach - %NaOCl in generic bleach % difference x100 %NaOCl in generic bleach 2. Write an executive summary that addresses the purpose of this lab, describing what was done and what was learned in this experiment, including any issues that were encountered and dealt with. Include critical values determined during the experiment. 3. Name 5 qualities of a good primary standard. 4. Why can t we use I 2 as a primary standard? 5. Place a copy of the Q-Table Critical values in your notebook for future reference. 6. Perform a Q-test on the following data. Draw a proper conclusion from your Q-test. Remember to state the calculated value of Q, the decision criteria, and the decision made. Data: 10.25mL 10.37mL 10.16mL 10.83mL 7. Most reactions that occurred during this experiment are oxidation/reduction reactions (Redox). For reactions 2, 3, and 4, fill in the following table. (Hint: decide for the iodine/iodide pair first and then fill in the oxyanions.) Reaction Substance Oxidized Substance Reduced Oxidizing Agent Reducing Agent Rev:

6 Rev:

7 Table 1: Standardization of Sodium Thiosulfate Solution. Mass of KIO 3 KIO 3 dissolved in ml H 2 O Mass of Na 2 S 2 O 3 5H 2 O Na 2 S 2 O 3 5H 2 O dissolved in ml H 2 O Run # (4) Aliquot Size (ml) Burette Ending Volume (ml) Burette Starting Volume (ml) Volume Delivered (ml) Note: All titrations also contained about: g KI and ml M HCl Table 2: Analysis of Bleach Name-brand Bleach Generic Bleach Run # 1 2 3* 1 2 3* Aliquot Size (ml) Burette Ending Volume (ml) Burette Starting Volume (ml) Volume Delivered (ml) %NaOCl Note: All titrations also contained about: g KI and ml M HCl * Run 3 is only required if assigned by instructor after review of runs 1 & 2 are completed for BOTH bleaches. Rev:

8 Rev:

Safety Note: Safety glasses and laboratory coats are required when performing this experiment

Safety Note: Safety glasses and laboratory coats are required when performing this experiment The Determination of Hypochlorite in Bleach Reading assignment: Burdge, Chemistry 4 th edition, section 4.6. We will study an example of a redox titration in order to determine the concentration of sodium

More information

Name Period Date. Lab 9: Analysis of Commercial Bleach

Name Period Date. Lab 9: Analysis of Commercial Bleach Name Period Date Lab 9: Analysis of Commercial Bleach Introduction Many common products are effective because they contain oxidizing agents. Some products, which contain oxidizing agents, are bleaches,

More information

EXPERIMENT 22 SOLUBILITY OF A SLIGHTLY SOLUBLE ELECTROLYTE

EXPERIMENT 22 SOLUBILITY OF A SLIGHTLY SOLUBLE ELECTROLYTE EXPERIMENT 22 SOLUBILITY OF A SLIGHTLY SOLUBLE ELECTROLYTE INTRODUCTION Electrolytes are compounds that are present in solution as ions. They are more likely to be soluble in water than in most other liquids

More information

Partner: Judy 29 March Analysis of a Commercial Bleach

Partner: Judy 29 March Analysis of a Commercial Bleach Partner: Judy 29 March 2012 Analysis of a Commercial Bleach Purpose: The purpose of this lab is to determine the amount of sodium hypochlorite (NaClO) in commercial bleach. This can be done by forming

More information

[Ca 2+ ] = s (3) [IO - 3 ] = 2s (4)

[Ca 2+ ] = s (3) [IO - 3 ] = 2s (4) E10 Chemical Equilibria: K sp of Calcium Iodate Objective! Understand the relation between the molar solubility and the solubility product constant of a sparingly soluble salt.! Measure the molar solubility

More information

$ % K st. K D [ I 2 ] Aqueous. [ I 2 ] Hexane. % Aqueous

$ % K st. K D [ I 2 ] Aqueous. [ I 2 ] Hexane. % Aqueous Determination of the Stability Constant of the Tri- Iodide Ion by Solvent Extraction Introduction Molecular iodine reacts with iodide to form a complex, called the tri- iodide ion, according to the reaction:

More information

Solubility Product Constant (K sp ) and the Common-Ion Effect for Calcium Iodate, a Salt of Limited Solubility

Solubility Product Constant (K sp ) and the Common-Ion Effect for Calcium Iodate, a Salt of Limited Solubility Solubility Product Constant (K sp ) and the Common-Ion Effect for Calcium Iodate, a Salt of Limited Solubility Purpose Determine the solubility product constant (K sp ) for a sparingly soluble salt. Study

More information

Copper (II) Glycinate Titration

Copper (II) Glycinate Titration Copper (II) Glycinate Titration In this experiment you will standardize (determine the concentration of) a solution of sodium thiosulfate. You will then use that sodium thiosulfate solution to titrate

More information

Chem 2115 Experiment #7. Volumetric Analysis & Consumer Chemistry Standardization of an unknown solution, analysis of vinegar & antacid tablets

Chem 2115 Experiment #7. Volumetric Analysis & Consumer Chemistry Standardization of an unknown solution, analysis of vinegar & antacid tablets Chem 2115 Experiment #7 Volumetric Analysis & Consumer Chemistry Standardization of an unknown solution, analysis of vinegar & antacid tablets OBJECTIVE: The goals of this experiment are to learn titration

More information

Analysis of Hypochlorite in Bleach

Analysis of Hypochlorite in Bleach Experiment 8 Analysis of Hypochlorite in Bleach Adapted by B. D. West and S. E. Schullery of Eastern Michigan University from ANAL 119, written by Enno Wolthuis, Calvin College, published by Chemical Education

More information

PURPOSE: 1. To illustrate an oxidation-reduction titration with potassium permanganate 2. To determine the percent mass of iron in an unknown.

PURPOSE: 1. To illustrate an oxidation-reduction titration with potassium permanganate 2. To determine the percent mass of iron in an unknown. PURPOSE: 1. To illustrate an oxidation-reduction titration with potassium permanganate 2. To determine the percent mass of iron in an unknown. PRINCIPLES: Oxidation and reduction reactions, commonly called

More information

Chem 2115 Experiment #7. Volumetric Analysis & Consumer Chemistry Standardization of an unknown solution and the analysis of antacid tablets

Chem 2115 Experiment #7. Volumetric Analysis & Consumer Chemistry Standardization of an unknown solution and the analysis of antacid tablets Chem 2115 Experiment #7 Volumetric Analysis & Consumer Chemistry Standardization of an unknown solution and the analysis of antacid tablets OBJECTIVE: The goals of this experiment are to learn titration

More information

EXPERIMENT 8 Determining K sp

EXPERIMENT 8 Determining K sp EXPERIMENT 8 Determining K sp Introduction The solubility product constant, or K sp of a compound is an equilibrium constant that describes the degree to which a solid dissolves in water. The K sp is calculated

More information

TITRATION OF AN ACID WITH A BASE

TITRATION OF AN ACID WITH A BASE TITRATION OF AN ACID WITH A BASE 1 NOTE: You are required to view the podcast entitled Use of Burets for Titrations before coming to lab this week. To view the podcast, consisting of eight episodes, go

More information

EXPERIMENT C3: SOLUBILITY PRODUCT & COMMON ION EFFECT. Learning Outcomes. Introduction. Upon completion of this lab, the student will be able to:

EXPERIMENT C3: SOLUBILITY PRODUCT & COMMON ION EFFECT. Learning Outcomes. Introduction. Upon completion of this lab, the student will be able to: 1 EXPERIMENT C3: SOLUBILITY PRODUCT & COMMON ION EFFECT Learning Outcomes Upon completion of this lab, the student will be able to: 1) Measure the solubility product constant for a sparingly soluble salt.

More information

Chemistry 1B Experiment 17 89

Chemistry 1B Experiment 17 89 Chemistry 1B Experiment 17 89 17 Thermodynamics of Borax Solubility Introduction In this experiment, you will determine the values of H and S for the reaction which occurs when borax (sodium tetraborate

More information

Acid-Base Titration. M M V a

Acid-Base Titration. M M V a Acid-Base Titration Pre-Lab Discussion In the chemistry laboratory, it is sometimes necessary to experimentally determine the concentration of an acid solution or a base solution. A procedure for making

More information

Experiment #7. Titration of Vinegar

Experiment #7. Titration of Vinegar Experiment #7. Titration of Vinegar Goals 1. To determine the mass percent of acetic acid in a solution via titration. 2. To master the technique of titration. Introduction Vinegar is a common household

More information

Molarity of Acetic Acid in Vinegar A Titration Experiment

Molarity of Acetic Acid in Vinegar A Titration Experiment Molarity of Acetic Acid in Vinegar A Titration Experiment Introduction Vinegar is prepared commercially in two steps, both requiring microorganisms. The first step is the production of ethyl alcohol, C

More information

E09. Exp 09 - Solubility. Solubility. Using Q. Solubility Equilibrium. This Weeks Experiment. Factors Effecting Solubility.

E09. Exp 09 - Solubility. Solubility. Using Q. Solubility Equilibrium. This Weeks Experiment. Factors Effecting Solubility. E09 Exp 09 - Solubility Solubility Solvation The reaction coefficient Precipitating Insoluble Substances Comparing Q to Ksp Solubility Equilibrium Solubility Product, Ksp Relating Molar Solubility Factors

More information

CHM111 Lab Titration of Vinegar Grading Rubric

CHM111 Lab Titration of Vinegar Grading Rubric Name Team Name CHM111 Lab Titration of Vinegar Grading Rubric Criteria Points possible Points earned Lab Performance Printed lab handout and rubric was brought to lab 3 Safety and proper waste disposal

More information

Experiment 7: ACID-BASE TITRATION: STANDARDIZATION OF A SOLUTION

Experiment 7: ACID-BASE TITRATION: STANDARDIZATION OF A SOLUTION Experiment 7: ACID-BASE TITRATION: STANDARDIZATION OF A SOLUTION Purpose: Determine molarity of a solution of unknown concentration by performing acid-base titrations Performance Goals: Apply the concepts

More information

Chesapeake Campus Chemistry 111 Laboratory

Chesapeake Campus Chemistry 111 Laboratory Chesapeake Campus Chemistry 111 Laboratory Objectives Calculate the concentration of a secondary standard through titration with a primary standard. Titrate a sample of carbonated soda with a standard

More information

Experiment 18 - Absorption Spectroscopy and Beer s Law: Analysis of Cu 2+

Experiment 18 - Absorption Spectroscopy and Beer s Law: Analysis of Cu 2+ Experiment 18 - Absorption Spectroscopy and Beer s Law: Analysis of Cu 2+ Many substances absorb light. When light is absorbed, electrons in the ground state are excited to higher energy levels. Colored

More information

Experiment 20-Acid-Base Titration: Standardization of KOH and Determination of the Molarity and/or Percent Composition of an Acid Solution

Experiment 20-Acid-Base Titration: Standardization of KOH and Determination of the Molarity and/or Percent Composition of an Acid Solution Experiment 20-Acid-Base Titration: Standardization of KOH and Determination of the Molarity and/or Percent Composition of an Acid Solution In this experiment, you will determine the molarity and percent

More information

PURPOSE: To determine the Rate Law for the following chemical reaction:

PURPOSE: To determine the Rate Law for the following chemical reaction: PURPOSE: To determine the Rate Law for the following chemical reaction: H 2 O 2 (aq) + 2 I - (aq) + 2 H 3 O + (aq) 4 H 2 O(l) + I 2 (aq) Hydrogen Iodide Hydronium Water Iodine Peroxide Ion Ion PRINCIPLES:

More information

Thermodynamics and the Solubility of Sodium Tetraborate Decahydrate

Thermodynamics and the Solubility of Sodium Tetraborate Decahydrate Thermodynamics and the Solubility of Sodium Tetraborate Decahydrate In this experiment you, as a class, will determine the solubility of sodium tetraborate decahydrate (Na 2 B 4 O 7 10 H 2 O or Na 2 [B

More information

8 Titration of Acids and bases

8 Titration of Acids and bases 8 Titration of Acids and bases Name: Date: Section: Objectives Reinforce acid-base chemistry principles from chapter 4 in Silberberg Standardize a sodium hydroxide solution Determine the molarity of an

More information

Experiment #10: Analysis of Antacids

Experiment #10: Analysis of Antacids Experiment #10: Analysis of Antacids Purpose: In this experiment you will prepare one solution that is approximately 0.1 M NaOH. Then you will standardize this solution, which means that you will experimentally

More information

Experiment 5: Determining the Stoichiometry and Products of a Redox Reaction

Experiment 5: Determining the Stoichiometry and Products of a Redox Reaction Experiment 5: Determining the Stoichiometry and Products of a Redox Reaction Reading: Chapter sections 4.4-4.6 and 20.1-20.2 in your course text and this lab handout Ongoing Learning Goals: To use a scientific

More information

Acid-Base Titrations

Acid-Base Titrations Chem 1252, General Chemistry I Lab Johnson Acid-Base Titrations Introduction Titration is a convenient quantitative method for accurately determining unknown concentrations of solutions. A necessary requirement

More information

NEUTRALIZATION TITRATION-2 TITRATION OF AN ANTACID (Exp. 4)

NEUTRALIZATION TITRATION-2 TITRATION OF AN ANTACID (Exp. 4) Objective NEUTRALIZATION TITRATION-2 TITRATION OF AN ANTACID (Exp. 4) The aim of this experiment is to carry out titration of antacid tablets and to determine acetic acid content of vinegar. a) Titration

More information

TRATION: ANALYSIS OF VINE

TRATION: ANALYSIS OF VINE Experiment 10 Name: 22 Ti TRATION: ANALYSIS OF VINE 31 Ga R In this experiment, you will learn the concept and technique of titration. You will determine the concentration of acetic acid in commercial

More information

O H 3 O 1 1 A. O 1 1 OH (K w

O H 3 O 1 1 A. O 1 1 OH (K w CHAPTER 8 Acid Base Titration Curves Objectives The objectives of this experiment are to: Understand the titration curves for the following solutions: a strong acid: hydrochloric acid, HCl. a weak acid:

More information

In this laboratory exercise we will determine the percentage Acetic Acid (CH 3 CO 2 H) in Vinegar.

In this laboratory exercise we will determine the percentage Acetic Acid (CH 3 CO 2 H) in Vinegar. The titration of Acetic Acid in Vinegar In this laboratory exercise we will determine the percentage Acetic Acid (CH CO H) in Vinegar. We will do this by Titrating the Acetic Acid present with a Strong

More information

EXPERIMENT A7: VINEGAR TITRATION. Learning Outcomes. Introduction. Upon completion of this lab, the student will be able to:

EXPERIMENT A7: VINEGAR TITRATION. Learning Outcomes. Introduction. Upon completion of this lab, the student will be able to: 1 Learning Outcomes EXPERIMENT A7: VINEGAR TITRATION Upon completion of this lab, the student will be able to: 1) Prepare a solution of primary standard 2) Determine the molar concentration of a solution

More information

EXPT. 8 IODOMETRIC DETERMINATION OF AVAILABLE CHLORINE IN A SAMPLE OF BLEACHING POWDER

EXPT. 8 IODOMETRIC DETERMINATION OF AVAILABLE CHLORINE IN A SAMPLE OF BLEACHING POWDER EXPT. 8 IODOMETRIC DETERMINATION OF AVAILABLE CHLORINE IN A SAMPLE OF BLEACHING POWDER Structure 8.1 Introduction Objectives 8. Principle 8.3 Requirements 8.4 Solutions Provided 8.5 Procedure 8.6 Observations

More information

Experiment 20: Analysis of Vinegar. Materials:

Experiment 20: Analysis of Vinegar. Materials: Experiment 20: Analysis of Vinegar Materials: graduated cylinder 6 M NaOH: Dilute Sodium Hydroxide 1000 ml Florence Flask & stopper KHC 8 H 4 O 4 : Potassium Hydrogen Phthalate (KHP) 125 ml Erlenmeyer

More information

Lab #5 - Limiting Reagent

Lab #5 - Limiting Reagent Objective Chesapeake Campus Chemistry 111 Laboratory Lab #5 - Limiting Reagent Use stoichiometry to determine the limiting reactant. Calculate the theoretical yield. Calculate the percent yield of a reaction.

More information

H 3 O + (aq) + P 2- (aq)

H 3 O + (aq) + P 2- (aq) PURPOSE: To standardize a solution of sodium hydroxide by titration with a primary standard, (KHC 8 H 4 O 4 ), potassium hydrogen phthalate (KHC 8 H 4 O 4 ) PRINCIPLES: Most shelf reagents, such as 0.10

More information

Acid-Base Titration Acetic Acid Content of Vinegar

Acid-Base Titration Acetic Acid Content of Vinegar Acid-Base Titration Acetic Acid Content of Vinegar Prelab Assignment Read the entire lab. Write an objective and any hazards associated with this lab in your laboratory notebook. On a separate sheet of

More information

Experiment 7A ANALYSIS OF BRASS

Experiment 7A ANALYSIS OF BRASS Experiment 7A ANALYSIS OF BRASS FV 10/21/10 MATERIALS: Spectronic 20 spectrophotometers, 2 cuvettes, brass sample, 7 M HNO 3, 0.100 M CuSO 4, 2 M NH 3, two 50 ml beakers, 100 ml beaker, two 25 ml volumetric

More information

EXPERIMENT #8 Acid-Base I: Titration Techniques

EXPERIMENT #8 Acid-Base I: Titration Techniques EXPERIMENT #8 Acid-Base I: Titration Techniques OBJECTIVES: Dispense a precise volume of a solution with a buret Titrate a known volume of acid solution with a standard solution of base Reach a proper

More information

Determination of the K a Value and Molar Mass of an Unknown Weak Acid

Determination of the K a Value and Molar Mass of an Unknown Weak Acid 10 Determination of the K a Value and Molar Mass of an Unknown Weak Acid Introduction In this experiment you will titrate a monoprotic weak acid with a strong base, and measure the titration curve with

More information

+ H 2 O Equation 1. + NaOH CO 2 Na

+ H 2 O Equation 1. + NaOH CO 2 Na Experiment # 5 VINEGAR: AN FDA INVESTIGATION Objective In this experiment, you will play the role of an FDA analytical chemist, You will verify whether a vinegar manufacturer's quality control lab remains

More information

EXPERIMENT A4: PRECIPITATION REACTION AND THE LIMITING REAGENT. Learning Outcomes. Introduction

EXPERIMENT A4: PRECIPITATION REACTION AND THE LIMITING REAGENT. Learning Outcomes. Introduction 1 EXPERIMENT A4: PRECIPITATION REACTION AND THE LIMITING REAGENT Learning Outcomes Upon completion of this lab, the student will be able to: 1) Demonstrate the formation of a precipitate in a chemical

More information

Determining the Rate Law for a Chemical Reaction

Determining the Rate Law for a Chemical Reaction Determining the Rate Law for a Chemical Reaction Purpose: To determine the reaction orders, rate law, and rate constant for the reaction between persulfate ions, SO8 -, and iodide ions, I - Introduction

More information

Acid Base Titration Experiment ACID - BASE TITRATION LAB

Acid Base Titration Experiment ACID - BASE TITRATION LAB ACID - BASE TITRATION LAB MATERIALS and CHEMICALS Burette 50 ml Burette clamp Ring stand Stirring rod Plastic funnel Beakers (50 ml, 100 ml, 400 ml) Graduated cylinder (25 ml, 50 ml) 0.10 M NaOH 0.10 M

More information

Exercise 6: Determination of Hardness of Water

Exercise 6: Determination of Hardness of Water Fundamentals of Analytical Chemistry, CHC014011L Exercise 6: Determination of Hardness of Water Introduction: Hardness in water is generally caused by the presence of dissolved calcium and magnesium carbonates

More information

Volumetric Analysis: Analysis of antacid tablets Analysis of Cl - concentrations in IV solutions

Volumetric Analysis: Analysis of antacid tablets Analysis of Cl - concentrations in IV solutions Volumetric Analysis: Analysis of antacid tablets Analysis of Cl - concentrations in IV solutions OBJECTIVE: The goals of this experiment are to learn titration concepts and techniques. SKILLS: Titration,

More information

Ascorbic Acid Titration of Vitamin C Tablets

Ascorbic Acid Titration of Vitamin C Tablets Ascorbic Acid Titration of Vitamin C Tablets Part A. Preparation of Vitamin C Tablet Solutions 1. Obtain two vitamin C tablets. Place a plastic weighing boat on the balance, and press zero to tare the

More information

Experiment 13H THE REACTION OF RED FOOD COLOR WITH BLEACH 1

Experiment 13H THE REACTION OF RED FOOD COLOR WITH BLEACH 1 Experiment 13H 08/03/2017 AHRM THE REACTION OF RED FOOD COLOR WITH BLEACH 1 PROBLEM: Determine the rate law for the chemical reaction between FD&C Red Dye #3 and sodium hypochlorite. LEARNING OBJECTIVES:

More information

Titration with an Acid and a Base

Titration with an Acid and a Base Skills Practice Titration with an Acid and a Base Titration is a process in which you determine the concentration of a solution by measuring what volume of that solution is needed to react completely with

More information

Experiment 2: Reaction Stoichiometry by Thermometric Titration

Experiment 2: Reaction Stoichiometry by Thermometric Titration Experiment 2: Reaction Stoichiometry by Thermometric Titration Introduction The net result of a reaction (a chemical change) is summarized by a chemical equation. In order to write a chemical equation,

More information

Chemical Reactions: Titrations

Chemical Reactions: Titrations 1 Chemical Reactions: Titrations ORGANIZATION Mode: laboratory work, work in pairs Grading: lab notes, lab performance (titration accuracy), and post-lab report Safety: goggles, lab coat, closed-toe shoes,

More information

NaOH (aq) + HCl (aq) NaCl (aq) + H 2 O (l)

NaOH (aq) + HCl (aq) NaCl (aq) + H 2 O (l) EXPERIMENT 21 Molarity of a Hydrochloric Acid Solution by Titration INTRODUCTION Volumetric analysis is a general term meaning any method in which a volume measurement is the critical operation; however,

More information

Experiment: Titration

Experiment: Titration Experiment: Titration INTRODUCTION In this experiment you will be determining the volume of sodium hydroxide solution of known concentration required to neutralize a known mass of an unknown acid in solution.

More information

Synthesis and Analysis of a Coordination Compound

Synthesis and Analysis of a Coordination Compound Synthesis and Analysis of a Coordination Compound In addition to forming salts with anions, transition metal cations can also associate with neutral molecules (and ions) through a process called ligation.

More information

Acid / Base Titrations

Acid / Base Titrations Acid / Base Titrations v051413_7pm Objectives: Determine the concentration of a base solution using an acid standard. Optional: Precipitate an ionic salt for percent yield determination using the standardized

More information

Solution Chemistry: Making Solutions, Reactions, and Solubility

Solution Chemistry: Making Solutions, Reactions, and Solubility 1 Solution Chemistry: Making Solutions, Reactions, and Solubility ORGANIZATION Mode: laboratory, groups of 4 Grading: goggles, closed-toe shoes, appropriate attire Safety: lab report, individual, due at

More information

EXPERIMENT. Estimate the strength of given sodium carbonate solution by titrating it against HCl solution using methyl orange as indicator.

EXPERIMENT. Estimate the strength of given sodium carbonate solution by titrating it against HCl solution using methyl orange as indicator. EXPERIMENT AIM Estimate the strength of given sodium carbonate solution by titrating it against HCl solution using methyl orange as indicator. Approximately M/40 HCl solution is provided. Prepare your

More information

Chemistry 1B Experiment 11 49

Chemistry 1B Experiment 11 49 Chemistry 1B Experiment 11 49 11 Buffer Solutions Introduction Any solution that contains both a weak acid HA and its conjugate base A in significant amounts is a buffer solution. A buffer is a solution

More information

6 Acid Base Titration

6 Acid Base Titration E x p e r i m e n t Acid Base Titration Experiment : http://genchemlab.wordpress.com/-titration/ objectives To understand the concept of titration. To explain the difference between the analyte and standard

More information

Name: Date: AP Chemistry. Titrations - Volumetric Analysis. Steps for Solving Titration Problems

Name: Date: AP Chemistry. Titrations - Volumetric Analysis. Steps for Solving Titration Problems Name: Date: AP Chemistry Titrations - Volumetric Analysis Term Volumetric analysis Burette Pipette titrate titre aliquot end point equivalence point indicator primary standard standardisation secondary

More information

To see how this data can be used, follow the titration of hydrofluoric acid against sodium hydroxide:

To see how this data can be used, follow the titration of hydrofluoric acid against sodium hydroxide: Weak Acid Titration v010516 You are encouraged to carefully read the following sections in Tro (3 rd ed.) to prepare for this experiment: Sec 4.8, pp 168-174 (Acid/Base Titrations), Sec 16.4, pp 769-783

More information

STOICHIOMETRY AND THE CHEMICAL REACTION

STOICHIOMETRY AND THE CHEMICAL REACTION From Laboratory Manual for Guinn and Brewer s Essentials of General, Organic, and Biochemistry by Sara Selfe STOICHIOMETRY AND THE CHEMICAL REACTION You would be surprised at the number of chemical reactions

More information

Experiment 13I THE REACTION OF RED FOOD COLOR WITH BLEACH 1

Experiment 13I THE REACTION OF RED FOOD COLOR WITH BLEACH 1 Experiment 13I FV 1/11/16 THE REACTION OF RED FOOD COLOR WITH BLEACH 1 PROBLEM: Determine the rate law for the chemical reaction between FD&C Red Dye #3 and sodium hypochlorite. LEARNING OBJECTIVES: By

More information

Chemistry 143 Acid Base Titration Dr. Caddell. Titrating Acid

Chemistry 143 Acid Base Titration Dr. Caddell. Titrating Acid Titrating Acid In this lab you will first determine the concentration of sodium hydroxide in a stock solution that you prepare. You will then use that stock sodium hydroxide solution to titrate a solution

More information

2002 D Required 2001 D Required

2002 D Required 2001 D Required 2002 D Required A student is asked to determine the molar enthalpy of neutralization, H neut, for the reaction represented above. The student combines equal volumes of 1.0 M HCl and 1.0 M NaOH in an open

More information

CHEM 132 Lab 11 Western Carolina University

CHEM 132 Lab 11 Western Carolina University Name Lab Section Chemistry 132 Lab 11 How Effective is Your Antacid? Prelaboratory Exercise 1. How many grams of NaOH will you need to make 250 of 0.5 M NaOH solution? 2. What is the purpose of the first,

More information

When dealing with solids that one can weigh on a balance, determining the number of moles in a particular sample is simply:

When dealing with solids that one can weigh on a balance, determining the number of moles in a particular sample is simply: Experiment 2 Stoichiometry Solids and Solutions Determining the Molarity of a Solution Lab Owl Announcement: Upon completion of this lab, log onto OWL. A Lab Owl section should now appear in your courses

More information

Chemistry Determination of Mixed Acids

Chemistry Determination of Mixed Acids Chemistry 3200 Acid-base titration is one of the most common operations in analytical chemistry. A solution containing an unknown amount of ionizable hydrogen can be titrated with a solution of standard

More information

GETTING THE END POINT TO APPROXIMATE. Two hours

GETTING THE END POINT TO APPROXIMATE. Two hours Chem 1312 Handout Experiment ONE Laboratory Time Required Special Equipment and Supplies Objective Safety First Aid GETTING THE END POINT TO APPROXIMATE THE EQUIVALENCE POINT Two hours Balance Potassium

More information

SOLVOLYSIS OF tert-butyl CHLORIDE: TESTING A MECHANISM

SOLVOLYSIS OF tert-butyl CHLORIDE: TESTING A MECHANISM SOLVOLYSIS OF tert-butyl CHLORIDE: TESTING A MECHANISM Organic chemists are keenly interested in how and why chemical reactions occur. They propose a plausible mechanism for a given reaction, then do experiments

More information

Studies of a Precipitation Reaction

Studies of a Precipitation Reaction Studies of a Precipitation Reaction Prelab Assignment Read the entire lab. Write an objective and any hazards associated with this lab in your laboratory notebook. Answer the following 6 questions in your

More information

9. Determination of the solubility product of KIO 4 and an investigation of the common ion effect Student Sheet

9. Determination of the solubility product of KIO 4 and an investigation of the common ion effect Student Sheet 9. Determination of the solubility product of KIO 4 and an investigation of the common ion effect Student Sheet This experiment will allow you to calculate a value for K sp, and also to see the common

More information

Experiment 8 Introduction to Volumetric Techniques I. Objectives

Experiment 8 Introduction to Volumetric Techniques I. Objectives Experiment 8 Introduction to Volumetric Techniques I Objectives 1. To learn the proper technique to use a volumetric pipette. 2. To learn the proper technique to use a volumetric flask. 3. To prepare a

More information

CHEM 30A EXPERIMENT 8 & 9: ACID- BASE TITRATION. Learning Outcomes. Introduction. Upon completion of this lab, the student will be able to:

CHEM 30A EXPERIMENT 8 & 9: ACID- BASE TITRATION. Learning Outcomes. Introduction. Upon completion of this lab, the student will be able to: 1 Learning Outcomes CHEM 30A EXPERIMENT 8 & 9: ACID- BASE TITRATION Upon completion of this lab, the student will be able to: 1) Prepare a solution of primary standard 2) Determine the molar concentration

More information

Ascorbic Acid Titration of Vitamin C Tablets

Ascorbic Acid Titration of Vitamin C Tablets Ascorbic Acid Titration of Vitamin C Tablets Introduction This experiment illustrates how titration, the process of slowly adding one solution to another until the reaction between the two is complete,

More information

Percentage of Acetic Acid in Vinegar

Percentage of Acetic Acid in Vinegar Microscale Percentage of Acetic Acid in Vinegar When sweet apple cider is fermented in the absence of oxygen, the product is an acid, vinegar. Most commercial vinegars are made by fermentation, but some,

More information

Titrations Worksheet and Lab

Titrations Worksheet and Lab Titrations Worksheet and Lab Vocabulary 1. Buret: a piece of glassware used for dispensing accurate volumes, generally reads to two places of decimal. 2. Titrant: the substance of known concentration added

More information

EXPERIMENT 5 ACID-BASE TITRATION

EXPERIMENT 5 ACID-BASE TITRATION EXPERIMENT 5 ACID-BASE TITRATION INTRODUCTION Much of chemistry and biology is concerned with the behavior of acids and bases. Acids and bases are participants in many reactions in nature, and many reactions

More information

Learn to do quantitative titration reactions. Observe the mole ratios of several simple chemical reactions.

Learn to do quantitative titration reactions. Observe the mole ratios of several simple chemical reactions. CHAPTER 6 Stoichiometry of Reactions in Solution Objectives The objectives of this laboratory are to: Learn to do quantitative titration reactions. Observe the mole ratios of several simple chemical reactions.

More information

Solubility Product Constants

Solubility Product Constants Solubility Product Constants PURPOSE To measure the solubility product constant (K sp ) of copper (II) iodate, Cu(IO 3 ) 2. GOALS To measure the molar solubility of a sparingly soluble salt in water. To

More information

PART II: ANALYSIS OF IRON COORDINATION COMPOUND

PART II: ANALYSIS OF IRON COORDINATION COMPOUND PART II: ANALYSIS OF IRON COORDINATION COMPOUND In this experiment students will perform two independent analyses of the iron coordination compound synthesized in Part I. A redox titration with potassium

More information

NOTE: YOU WILL BE USING THIS SOLUTION IN BOTH, THIS EXPERIMENT AND EXP 12B. IF YOU WASTE THE SOLUTION YOU MAY RUN OUT BEFORE YOU HAVE FINISHED EXP 12B

NOTE: YOU WILL BE USING THIS SOLUTION IN BOTH, THIS EXPERIMENT AND EXP 12B. IF YOU WASTE THE SOLUTION YOU MAY RUN OUT BEFORE YOU HAVE FINISHED EXP 12B EXPERIMENT 12 A: STANDARDIZATION OF A SODIUM HYDROXIDE SOLUTION OBJECTIVE: Sodium hydroxide solution of about 0.2 M is prepared in order to be used in Exp 12B. The solution is then standardized, that is,

More information

Upon completion of this lab, the student will be able to:

Upon completion of this lab, the student will be able to: 1 Learning Outcomes EXPERIMENT 30A7: VINEGAR TITRATION Upon completion of this lab, the student will be able to: 1) Measure the amount of acetic acid in a solution of vinegar Introduction The molar concentration

More information

Chemistry 143 Experiment #11 Acid Base Titration Dr. Caddell. Titrating Acid

Chemistry 143 Experiment #11 Acid Base Titration Dr. Caddell. Titrating Acid Titrating Acid In this lab you will first determine the concentration of sodium hydroxide in a stock solution that you prepare. You will then use that stock sodium hydroxide solution to titrate a solution

More information

DETERMINATION OF THE SOLUBILITY PRODUCT OF GROUPII HYDROXIDES

DETERMINATION OF THE SOLUBILITY PRODUCT OF GROUPII HYDROXIDES INTRODUCTION DETERMINATION OF THE SOLUBILITY PRODUCT OF GROUPII HYDROXIDES SOLUBILTY EQUILIBRIA Many systems in chemistry appear to be static when in fact they are in (dynamic) equilibrium. When a system

More information

experiment7 Explaining the difference between analyte and standard solutions. Know the definition of equivalence point.

experiment7 Explaining the difference between analyte and standard solutions. Know the definition of equivalence point. 93 experiment7 Determining an Unknown Concentration Understanding the concept of titration. LECTURE AND LAB SKILLS EMPHASIZED Explaining the difference between analyte and standard solutions. Know the

More information

EXPERIMENT NINE Part I - The Standardization of Thiosulfate Solutions

EXPERIMENT NINE Part I - The Standardization of Thiosulfate Solutions EXPERIMENT NINE Part I - The Standardization of Thiosulfate Solutions In general, thiosulfate solutions are standardized by indirect methods, Primary-standard oxidizing agents such as KIO 3, As 2 O 3,

More information

7-A. Inquiry INVESTIGATION. 322 MHR Unit 3 Quantities in Chemical Reactions. Skill Check. Safety Precautions

7-A. Inquiry INVESTIGATION. 322 MHR Unit 3 Quantities in Chemical Reactions. Skill Check. Safety Precautions Inquiry INVESTIGATION 7-A Skill Check Initiating and Planning Performing and Recording Analyzing and Interpreting Communicating Safety Precautions Wear safety eyewear throughout this investigation. Wear

More information

Ascorbic Acid Titration of Vitamin C Tablets

Ascorbic Acid Titration of Vitamin C Tablets Ascorbic Acid Titration of Vitamin C Tablets Introduction This experiment illustrates how titration, the process of slowly adding one solution to another until the reaction between the two is complete,

More information

CHM112 Lab Iodine Clock Reaction Part 2 Grading Rubric

CHM112 Lab Iodine Clock Reaction Part 2 Grading Rubric Name Team Name CHM112 Lab Iodine Clock Reaction Part 2 Grading Rubric Criteria Points possible Points earned Lab Performance Printed lab handout and rubric was brought to lab 3 Initial concentrations completed

More information

Experimental Procedure. Lab 406

Experimental Procedure. Lab 406 Experimental Procedure Lab 406 Overview This experiment is to be complete in cooperation with other chemists/chemist groups in the laboratory. In PART A, a standardized solution of hydrochloric acid is

More information

CIE Chemistry A-Level Practicals for Papers 3 and 5

CIE Chemistry A-Level Practicals for Papers 3 and 5 CIE Chemistry A-Level Practicals for Papers 3 and 5 Rate of Reaction Disappearing cross: Change in rate of the reaction of sodium thiosulphate with hydrochloric acid as temperature is changed: Na 2 S 2

More information

Volumetric analysis involving acids and alkalis

Volumetric analysis involving acids and alkalis Chapter 19 Volumetric analysis involving acids and alkalis 19.1 Standard solutions 19.2 Acid-alkali titrations 19.3 Calculations on volumetric analysis 19.4 Writing a laboratory report on volumetric analysis

More information

Chemistry 151 Last Updated Dec Lab 8: Precipitation Reactions and Limiting Reagents

Chemistry 151 Last Updated Dec Lab 8: Precipitation Reactions and Limiting Reagents Chemistry 151 Last Updated Dec. 2013 Lab 8: Precipitation Reactions and Limiting Reagents Introduction In this lab you will perform a simple precipitation reaction between strontium nitrate and potassium

More information

Experiment #5. Iodine Clock Reaction Part 1

Experiment #5. Iodine Clock Reaction Part 1 Experiment #5. Iodine Clock Reaction Part 1 Introduction In this experiment you will determine the Rate Law for the following oxidation- reduction reaction: 2 H + (aq) + 2 I (aq) + H 2 O 2 (aq) I 2 (aq)

More information

Experiment 7: Titration of an Antacid

Experiment 7: Titration of an Antacid 1 Experiment 7: Titration of an Antacid Objective: In this experiment, you will standardize a solution of base using the analytical technique known as titration. Using this standardized solution, you will

More information