INSTRUCTOR MANUAL - CHEMISTRY A MOLECULAR APPROACH Fifth Edition NI...

INSTRUCTOR MANUAL

FOR

LABORATORY MANUAL

John B. Vincent • Erica Livingston

CHEMISTRY

A MOLECULAR APPROACH

Fifth Edition

NIVALDO J. TRO 1 / 4

iii Copyright © 2020 Pearson Education, Inc.

Table of Contents Experiment 1 Laboratory Basics: Accuracy and Precision – Who’s the Shooting Champion? 1 Experiment 2 Components of a Mixture – What is That Stuff in the Bottom of the Cereal Box? 3 Experiment 3 Cathode Ray Tubes, Millikan Oil Drop, Speed of Light, and Avogadro’s Number 5 Experiment 4 Conservation of Mass and Reaction Types – Copper Recovery Cycle 9 Experiment 5 Equivalent Weights and the Periodic Table 11 Experiment 6 Hydrates 13 Experiment 7 Gas Laws 15

Experiment 8 Styrofoam Cup Calorimetry: Atomic Weights 17

Experiment 9 Chemiluminescence: Glow Stick in a Beaker 20

Experiment 10 Atomic Spectra 23 Experiment 11 Reactivity of Group 1 Metals – Yes, Mom, I Threw Sodium in Water in Class Today 24 Experiment 12 Flame Tests – Flames and Smoke Bombs 27 Experiment 13 VSEPR and Molecular Models 30

Experiment 14 Simulating the Shroud of Turin: An Inquiry-Based Experiment 32

Experiment 15A Observe the Rainbow: Paper Chromatography 35

Experiment 15B Chemical Oil Dispersant Experiment 37 Experiment 16 Sublimation 42 Experiment 17 Closest Packed Structures 44 Experiment 18 Colligative Properties – Freezing Point Depression 48 Experiment 19A Diet Coke and Mentos – An Inquiry-Based Experiment 50

Experiment 19B Kinetics: Testing for Semen – Acid Phosphatase 52

Experiment 19C Activation Energy Determination 55 Experiment 20 Equilibrium Constants and LeChatelier’s Principle – CoCl2 57 Experiment 21 Far from Equilibrium Systems – Creating Life in a Beaker 62 Experiment 22 Acid-base Titration 64 Experiment 23 Determining the Buffer Capacity of Antacids 66 Experiment 24 Entropy – The Chelate Effect 68 Experiment 25 Redox Reactions – Detecting Traces of Blood 70 Experiment 26 Radioactivity 73 Experiment 27A Group I Cations 76 Experiment 27B Group II Cations: “I love the Smell of Hydrogen Sulfide – It Smells like Victory” 78

Experiment 27C Group III: Piltdown Man and Scientific Ethics 81

Experiment 27D Group IV Cations 84 Experiment 27E Anions 86 Experiment 28 Esters 88 Experiment 29 Which Compounds Are Genotoxic or Carcinogenic? – Cleaving Plasmid DNA and Gel Electrophoresis

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1 Copyright © 2020 Pearson Education, Inc.

Experiment 1

Laboratory Basics: Accuracy and Precision – Who’s the Shooting

Champion?

For the Instructor

This lab is designed to add fun and excitement to the traditional first experiment in the first-semester general chemistry laboratory. For shooting at a target, we would recommend being open to experimentation. A large catapult throwing water balloons at a large target such as a sheet painted with a bull’s eye, a paint ball gun and target, blunt-tipped arrows shot into a target mounted on a thin piece of styrofoam, throwing horseshoes, rolling balls into a bull’s eye, throwing small bean bags (as in tail gate toss) at a target, chipping golf balls at a flag, or even just darts and a dart board can be considered. A safe indoor alternative is foam dart guns; these darts can be fired at a target drawn on a dry erase board or chalk board. Cost is only around $10, and they can be found at most toy stores.Moistening the end of the suction cups helps the dart to adhere to the target.

In our experience, 10 mL disposable plastic centrifuge tubes are surprisingly accurate, just as accurate within error as 10 mL graduated cylinders. However, because the tubes have fewer graduations, estimating the last significant figure when adding a given mass of water is more difficult. We have also found that the reproducibility of measuring 8 mL of water is greater with the plastic tubes compared to the graduated cylinder as it is easier in the plastic to gently tape the container to remove air bubbles and water droplets clinging to the side.

Preparation Information – 24 students

Shooting mechanism (refer to previous discussion) 1 per group Compass or string 10- or 15-mL plastic centrifuge tube with cap 1 per group Weigh boats (capable of holding 8 mL water) 1 per group

Necessary Equipment – 24 students

Paper towels Disposable gloves Balance 4 or 5 per room 10-mL graduated cylinder 1 per group

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Experiment 1: Laboratory Basics: Accuracy and Precision – Who’s the Shooting Champion?2 Copyright © 2020 Pearson Education, Inc.

Answers to Pre-Laboratory Questions

• William Tell had only one shot to shoot an apple from the top of his son’s head with his bow and

arrow. If you were William Tell and you loved your son, would you rather be accurate or precise?Explain why.

Accurate – hit the apple. Precise refers to reproducibility, which is not applicable with one shot.

• Assume that you found that the average volume of water required to fill the graduated cylinder to

the 8.00 mL mark was 7.95 mL. Calculate the % error.

(7.95 mL − 8.00 mL)/8.00 mL × 100% = 6%

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