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EXTENDED LEARNING INSTITUTE NORTHERN VIRGINIA COMMUNITY COLLEGE LABORATORY GUID

EXTENDED LEARNING INSTITUTE NORTHERN VIRGINIA COMMUNITY COLLEGE LABORATORY GUIDE ELI HOTLINE: (703) 323-3347 V/TDD: (703) 323-3717 Version 1/02 CHM 111 CHM 111 College Chemistry I Copyright © 2002 by Northern Virginia Community College. All rights reserved. CHM 111 Laboratory Guide Table of Contents Overview of CHM 111 Laboratory Component.............................................................1 On-Campus Laboratory Experiments.................................................................1 Off-Campus Laboratory Exercises.....................................................................2 Policies and Procedures for On-Campus Laboratories..............................................3 Prelaboratory for Dry Lab 3 -- Chemical Models: Lewis Structures..........................5 Instructions for Off-Campus Laboratory Exercises..................................................14 Inorganic Nomenclature....................................................................................15 Scientific Literature............................................................................................32 Exercise 1: Library Information Retrieval.............................................33 Exercise 2: Research Report..................................................................34 Smithsonian Lab Exercises...............................................................................35 Exercise 1: Hands-on Science Center...................................................36 Exercise 2: “Science in American Life” Exhibit...................................37 Chromatography of Food Dyes.........................................................................38 Overview of CHM 111 Laboratory Component The laboratory component of the ELI course CHM 111, College Chemistry I, consists of ten laboratory exercises: four on-campus laboratory experiments, one Lab Safety, Orientation, and Techniques, one Nomenclature Lab and Test, three CyberChem CD-ROM CyberLabs, and your choice of one out of five off-campus experiments. On-Campus Laboratory Experiments (all are mandatory) Scheduling Four experiments are scheduled in the chemistry lab on Annandale Campus on Saturdays from 9:00 am to 3:30 pm during the semester. These are to be done in groups of four students. These experiments have been selected from the Laboratory Manual for Principles of General Chemistry, 6th Edition. These are: 1. Experiment 2: Identification of a Compound: Physical Properties -- read the textbook assignments for Units 1 and 2 2. Experiment 9: A Volumetric Analysis -- read the textbook assignments for Units 3 & 4 3. Experiment 12: Inorganic Compounds and Metathesis Reactions -- read the textbook assignments for Units 3 and 4 4. Dry Lab 3: Atomic and Molecular Structure -- read the textbook assignments for Units 7, 8, and 9; also complete the Prelaboratory assignment (Chemical Models: Lewis Structures) on pages 5 - 12 of this Lab Guide. Complete the Prelaboratory Assignment questions in the Laboratory Manual for each scheduled experiment individually, not in groups. Submit it to the instructor in Lab. Perform each experiment and submit a Lab Report as per the described format. Allow three hours to complete one experiment. You must plan to do two experiments on each Saturday, 9-12 and 12:30-3:30 Preparation for first on-campus laboratory experiment Before reporting to the Annandale Campus chemistry lab for the first time, you should: a. complete Assignment 0 (see your online Course Guide) including your Course Completion Plan on the online forum. b. Do the Lab Safety, Orientation, and Techniques off-campus lab (see instructions in the Off-Campus Laboratory Exercises section on the next page). c. read the  Procedures and Policies for On-Campus Laboratories section of this Guide. d. view the Lab Safety Video in one of the campus libraries and take the Lab Safety quiz 1 (available at any NVCC campus Testing Center). Note: you must pass this safety quiz and present a form certifying this to the lab instructor in order to be admitted to the lab. Off-campus Laboratory Exercises Mandatory Exercises: 5. Lab Safety, Orientation, and Techniques -- Read Laboratory Safety and Guidelines, Laboratory Data, and Laboratory Techniques sections; Read Dry Lab 1, complete Sections A through D and submit pages 35-36 and pages 41-42 stapled together 6. Inorganic Nomenclature Lab and Nomenclature Test 7. CyberLab 3: Combustion Analysis -- read textbook assignments for Unit 3 8. CyberLab 4: Precipitation Reactions -- read textbook assignments for Units 3 & 4 9. CyberLab 6: Hess’ Law -- read textbook assignments for Unit 6 Complete instructions for Lab 6 is found in the Instructions for Off-Campus Laboratory Exercises section of this Laboratory Guide. Complete instructions for the three CyberLabs (CyberLabs 3, 4, and 6) are found on the Cyber- Chem CD-ROM. For the CyberLabs, after performing each experiment submit a Lab Report using the format described in the Procedures and Policies for On-Campus Laboratories section of this Laboratory Guide. Optional Exercises: Choose one of the following five experiments: 10a. Scientific Literature: Library Information Retrieval 10b. Scientific Literature: Research Report 10c. Smithsonian Institution: Visit to “Science in American Life” exhibit 10d. Smithsonian Institution: Visit to “Hands-on Science Center” 10e. Chromatography of M&M Candies Complete instructions for these optional labs are found in the Instructions for Off-Campus Laboratory Exercises section of this Laboratory Guide. 2 Procedures and Policies for On-Campus Laboratories During the lab - Identify one member of your laboratory group to be the designated leader for the experiment. This person will take the official set of data and observations during the lab and coordinate the preparation of the lab report. - Each member of the group should record notes, observations and data on the Data Sheet provided in the laboratory module. These data and observations are to be written in ink. - Follow all general laboratory safety rules and specific safety precautions and disposal procedures for the experiment. - Have the instructor initial the official copies of all data and observations that will be turned as part of the lab report. Following the lab Complete and submit a lab report within 2 weeks after performing the experiment. One lab report will be submitted by each group. The content of the report should include the following: Cover page: Includes lab section, the names of the group members who performed the experiment and contributed to the writing of the report; number and name of the experiment, date performed, and date due. Body of report -- This part of the report will contain: • An introduction stating the purpose of the lab exercise and a brief description of procedures followed. • The "official" Data Sheet from the lab module exactly as completed during the experiment. • A page or pages showing all calculations hand written in pencil. Calculations of experimental error are to be included if appropriate for the experiment. Units should be included for all calculations and the rules for significant figures followed. NOTE: It is important that you follow the rule that all observations and data be recorded in ink. These constitute an official and unchangeable record of the experiment. If there is disagreement within the group concerning a measurement or observation, it must be repeated. If the second determination differs from the original one, the original is crossed out with a single line also in ink and the new value entered. A notation is added explaining why repetition was necessary. It is essential that all observers agree on observation before it is recorded, and that each member of a group assume responsibility for assuring that everyone records the same data. If it is impossible to agree on an observation or measurement, even after repeating it, the details of the argument are to be included as part of the observation so they become part of the record. • A discussion of experimental results including: - an analysis of results comparing actual results with expected results, i.e. experimental accuracy; - a discussion of experimental error (random and systematic) and its possible sources as well as the precision of results. • A concluding statement summarizing how the experimental results relate to the objective of the experiment. • A statement from each individual group member describing his/her contribution to the report. If the lab experiment includes Post Laboratory Questions, these are to be completed by the group working together and one copy attached to the lab report. Prelaboratory Assignment for Dry Lab 3 Chemical Models: Lewis Structures The Problem to be Investigated: • Write Lewis structures for atoms, molecules, and ions. • Predict the empirical formulas of compounds and write their Lewis structures. • Write chemical equations using Lewis structures for the reactants and products. Background Information To understand better the nature of matter, chemists become involved in model building. The structure of a substance can often be pictured in the mind by constructing a physical model to represent it. By studying the model, predictions can often be made as to the possible physical and chemical behavior of the substance, and insight is often gained as to its shape and size. The atoms of a substance are held together by bonds. The nature of the bonding can be considered also by building a model of the substance. One type of model that is often used is the Lewis structure. This model shows the sequence of the atoms in the molecule and the distribution of the outer electrons of the atoms. In a Lewis structure, the chemical symbol of an element represents the nucleus and all the inner electrons of an atom of that element. This portion of the structure is sometimes called the atomic kernel. The outer electrons may be represented by dots added to the kernel. The number of outer electrons of an element may be determined from its position in the periodic table. The Roman numeral heading each group or column on the table indicates the number of outer electrons of each element in that group. When writing the Lewis structure for lithium, for example, the presence of Li in Group I of the periodic table indicates Li has one outer uploads/Ingenierie_Lourd/ chm111-lab-guide.pdf