Chem 253: Introduction to Quantitative Analysis Fall Semester 2007 Instructor: Office: Phone: Textbooks: Professor Peter R. Griffiths (pgriff@uidaho.edu) Renfrew Hall (REN) Room 001 885-5807 Exploring Chemical Analysis, 3rd Edition, Daniel C. Harris [Three copies of a more advanced textbook by Harris (Quantitative Chemical Analysis, 7th Edition, by Daniel C. Harris) will be on reserve in the library:] Calculator: An inexpensive calculator is required. You will need the calculator during labs and exams. It should have the capability for logarithms, exponentiation (antilogarithms), yx and scientific notation operations. TEXT ENTRY CALCULATORS WILL NOT BE PERMITTED TO BE USED DURING EXAMS OR QUIZZES. Two key or combination padlocks with up to 3/8 inch diameter shank Please bring the safety goggles that were given to you upon completion of your general chemistry classes. If you have lost these goggles, you should purchase another pair from ChemStores (Basement, Renfrew Hall). If you transferred her, you will be issued with a new pair of goggles free of charge. Only departmentally approved safety goggles will be permitted to be worn in the laboratory. It is Chemistry Department policy that safety goggles MUST be worn at all times in the laboratory or handling chemicals. In light of the fact that strong acids are frequently used in this course, neither sandals nor shorts may be worn in the laboratory.
Office Hours: 2:20 – 4:30 p.m., Mondays and Fridays
Padlock: Goggles:
Sandals:
Introduction: This course serves two primary purposes. The first is to reinforce much of what you already know about aqueous equilibria and to apply it to the determination of selected components in several types of samples. (Note that all students who are required to take Chem 253 must have a solid understanding of aqueous equilibria for their majors.) The second is to introduce you to ways of obtaining really accurate determinations of materials by three different approaches: volumetric analysis, gravimetric analysis and spectrophotometry. The theory behind each experiment will be covered in some detail in class.
The Labs: You will often be given a sample the concentration of which is accurately known by your TA. It will be your task to show that you can obtain a concentration to within one part per thousand (ppt) of the correct answer. Your sample is different from everyone else’s in the lab. (We purchase these samples from a company that has made very accurately prepared mixtures for over 50 years. I have never known one of these samples to be in error by as much as 1 ppt.) The only way to come close to the correct answer is to follow the lab procedures very carefully. Often the techniques that you have been taught in high school or in general chemistry are inadequate, so be sure to listen to your TA and read up about lab techniques in the textbook. If you don’t keep your glassware and the analytical balances scrupulously clean, your results will suffer. The balances you will use are accurate to 0.1 mg, provided that they are level and not abused. See your TA if you have any reason to believe that there is anything wrong with the balance you are using. If there is and you don’t do anything about it, your lab grade will suffer as a result. Remember that your task is to determine the exact concentration of one of the components of your sample to an accuracy of 1 ppt; if your balance is inaccurate, your results will be in error. A secondary goal of this course is to teach you to keep a good lab notebook. The lab book should be hard-bound, not spiral bound, with all pages numbered by you. All entries in your notebook must be in pen. Your lab grade will suffer any time your TA sees you either entering data in your notebook in pencil or writing something down on a scrap of paper to enter in your book later. Your notebook doesn’t have to be a work of art. It does have to be used to record everything that you did in the lab in a way that can be understood by you and by others (your TA and me, for example). Draw a simple line through the results of any experiment that you decide to reject and give the reason why you chose to reject this result. There will be a prelab question that is associated with each lab that is designed to ensure that you know how to calculate your results. Please hand in your answer to this question as you arrive in the lab. Anyone arriving more than 15 minutes late for the lab will receive a grade of zero for that question. Each measurement is done in triplicate and you should calculate the result immediately you have finished each run. If one result is obviously out of line with the other two (e.g., by the Q test), there is often time to carry out a fourth or even fifth run, so that you can discard the outlying result. Classes and Homework: I will spend most of each class period introducing you to a given topic. I will then assign a few pages out of Harris’s book for you to read, together with a few problems from the relevant chapter. At the start of the following class, I will spend a few minutes answering questions about my previous lecture or about the assigned reading material before introducing a new topic. Don’t be bashful about asking me to discuss any topic that you don’t understand. The answers to the questions will be posted on my web site. Every Friday, I will assign two problems (one easy and one difficult) that you should do; please give your answers to your TA on the following Tuesday lab.
Your Teaching Assistant: Each section has a different TA. If you have any questions on any material that you would prefer to ask your TA, please see him during his office hours in REN 049. Their office hours are as follows: Section 1 (T, Th morning lab lab): REN 337, TA: TBA Section 2 (T, Th afternoon lab): REN 337, TA: TBA Section 3 (T, Th evening lab) Section 4 (T, Th morning lab) REN 337, TA: TBA. REN 334, TA: TBA
If you can’t make it to your TA’s office hours, try to see one of the other Chem 253 TAs during his/her office hours. (They will know much more about the course material than any of the other TAs who are staffing REN 049 at other times.) Grading Policy: There will be three mid-term examinations and a comprehensive final. Your final grade will calculated in the following way: Mid-Terms 45% (15% each) Lab 25% Homework 10% Final 20% The grades will be as follows: A,100-80%; B, 79-65%;C, 64-55%; D, 54-45%; F, less than 45%. I don’t grade on a curve. If you can’t work out how well you are doing in the course at any point in the semester, you can work out your score by dividing your current score for a given category by the possible score and multiplying it by the percentage given above. Most people do about as well on the final as they do on the mid-term exams, and I make this assumption. Simply add the scores for each category to find your current score. Let us say that at a certain point in the semester, you have scored 387 out of a possible 500 in the lab, 58 out of a possible 70 points on the homework assignments and 72 and 68% on the first two mid-terms. Your current score would be: Lab: (387/500) x 25 = 19.35; Homework: (58/70) x 10 = 8.29; Exams: (140/200) x 65 = 45.50 Current projected score: 19.35 + 8.29 + 45.50 = 73.14, i.e., you currently have a B.
Approximate Schedule August 20 Introduction to the class August 22 Introduction to chemical analysis, units of concentration (to include “p functions”), accuracy and precision (Chapters 0, 1 and 2 and Appendix IA) August 24 The significance of data, introductory statistics (Ch. 3 and Appendix IIA) August 27 August 29 August 31 Sept. 3 Sept. 5 Sept. 7 Statistics, rejection of data (Chapter 4) Chemical equilibria, introduction to acids and bases (Sections 6-1 and 6-2, Sections 8-1 through 8-4) Activity; activity coefficients (Chapter 12) No class (Labor Day) Introduction to volumetric analysis, titration of strong acids and bases (Section 6-1 and 6-2, Section 10-1) Titration of Weak Acids and Bases (Sections, 8-5 through 8-7, 9-2, 10-2 through 10-6. Polyprotic acid-base equilibria and titrations (Chapter 11) Buffer solutions (Section 9-3 through 9-5) Acid-Base Indicators (Section 9-6) Review of statistics, acid and bases and neutralization titrations First Mid-Term Exam Introduction to Spectrophotometry (Chapter 18) Beer’s law and spectrophotometric analysis (Chapter 18) Applications of spectrophotometry (Chapters 19 and 20) Introduction to Precipitation (Section 6-4) The formation of precipitates (Not covered well in the textbook) Precipitation titrations (Sections 6-5 and 6-6 Gravimetric analysis (Chapter 7) Gravimetric analysis (Chapter 7) Effect of Ionic Strength and pH on Solubility Separation by precipitation (Section 9E) Review of specrophotometry, precipitation equilibria, precipitation titrations and gravimetric analysis Second Mid-Term Examination Complex formation (Sections 13-1 through 13-3) Complexometric titrations (Sections 13-4 through 13-6) Indicators for EDTA titrations (Section 13-3) Fundamentals of electrochemistry (Sections 14-1 and 14-2)
Sept. 10 Sept. 12 Sept. 14 Sept. 17 Sept. 19 Sept. 21 Sept. 24 Sept. 26 Sept. 28 Oct. 1 Oct. 3 Oct. 5 Oct. 8 Oct. 10 Oct. 12 Oct. 15 Oct. 17 Oct. 19 Oct. 22 Oct. 24 Oct. 26
Oct. 29 Oct. 31 Nov. 2 Nov. 5 Nov. 7 Nov. 9 Nov. 12 Nov. 14 Nov. 16 Nov. 19 Nov. 21 Nov. 23 Nov. 26 Nov. 28 Nov. 30 Dec. 3 Dec. 5 Dec. 7
The Nernst equation and standard electrode potentials (Sections 13-3 through 13-5) Redox titrations (Chapter 16) Redox titrations (Chapter 16) Potentiometry (Chapter 15) Reference electrodes (Chapter 14-6) pH and other Ion-Selective Electrodes (Sections 15-3 and 15-4) Review of potentiometry, redox titrations Third Mid-Term Examination on complexometric titrations and electrochemical methods Coulometric analysis (Section 17-1) No class (Thanksgiving break) No class (Thanksgiving break) No class (Thanksgiving break) Principles of Chromatography (Chapter 21) Gas chromatography (Section 22-1) Liquid chromatography (Sections 22-2 and 22-3) Other forms of chromatography (Chapter 23) Modern spectroscopy (Chapter 20) Review for final examination Final Examination
Dec. 10, 10:00 a.m.
IMPORTANT NOTICE: The final examination is scheduled at 10:00 a.m. on Moday, December 10. This is the first day of finals week. Everyone in the class is expected to take the exam at this time. No accommodation will be made for students who have made arrangements to have left Moscow by this time.
Laboratory Schedule First Lab Second Lab No lab Check in; clean glassware; instruction on balance
First Lab No class (Labor Day) Second Lab: Experiment 1: Use of analytical balance; dry KHP First Lab: Experiment 2: Preparation of standard solutions of NaOH and HCl Second Lab: Experiment 2: Determination of purity of impure KHP sample First Lab Second Lab First Lab Second Lab First Lab Second Lab First Lab Second Lab First Lab Second Lab First Lab Second Lab First Lab Second Lab First Lab Second Lab First Lab Second Lab First Lab Second Lab First Lab Second Lab First Lab Second Lab First Lab Second Lab Experiment 3: Volumetric analysis of a drain cleaner Experiment 3: Volumetric analysis of a drain cleaner Experiment 4: Spectrophotometric determination of manganese in steel Experiment 4: Spectrophotometric determination of manganese in steel Experiment 5: Spectrophotometric determination of copper in an alloy Experiment 5: Spectrophotometric determination of copper in an alloy Experiment 6: Volumetric determination of chloride by Fajan’s method Experiment 6: Volumetric determination of chloride by Fajan’s method Experiment 7: Gravimetric determination of chloride Experiment 7: Gravimetric determination of chloride Experiment 8: Gravimetric determination of iron Experiment 8: Gravimetric determination of iron Experiment 9: Complexometric determination of Ca and Mg in water Experiment 9: Complexometric determination of Ca and Mg in water Experiment 10: Determination of Vitamin C by redox titration Experiment 10: Determination of Vitamin C by redox titration Experiment 11: Potentiometric analysis of acid in soft drinks Experiment 11: Potentiometric analysis of acid in soft drinks No class (Thanksgiving break) No class (Thanksgiving break) Experiment 13: Coulometric acid-base titraton Free lab to catch up if you are behind Small Group Project Small Group Project Small Group Project Check out