INTRODUCTORY MATERIAL

• Find the Relationship: An Exercise in Graphing Analysis (40 min.)

Use a computer and graphing programs to determine mathematical relationships.

STATES OF MATTER

• Freezing and Melting of Water (40 min.)

Investigate and graph the cooling and warming behavior of water using LoggerPro and computer graphing programs.

• Another Look at Freezing Temperature (40 min.)

Observe what happens when phenyl salicylate freezes and see the effect on the freezing temperature when a small amount of benzoic acid is dissolved in the phenyl salicylate.

• Heat of Fusion of Ice (40 min.)

Determine the energy required to melt one gram of ice and the molar heat of fusion for ice.

• Evaporation and Intermolecular Attractions (40 min.)

Study temperature changes caused by the evaporation of several liquids and relate the temperature changes to the strength of the intermolecular forces of attraction.

• Using Freezing Point Depression to Find Molecular Weight (40 min.)

Find the freezing temperatures of pure lauric acid and then of benzoic acid and lauric acid. By measuring the freezing point depression and the mass of the benzoic acid, determine the molecular weight of the benzoic acid.

ENERGY

• Endothermic and Exothermic Reactions (40 min.)

Study one exothermic and one endothermic reaction. Use LoggerPro to collect and display data as a graph or table and analyze experimental data.

• Energy Content of Foods (40 min.)

Determine the energy released as various foods burn and look for patterns in the amount of energy released.

• Energy Content of Fuels (40 min.)

Use a Styrofoam-cup calorimeter to measure the heat released by three reactions. Calculate the heat of reaction for the three reactions and use the results to confirm Hess’s law.

• Additivity of Heats of Reaction: Hess's Law (40 min.)

Find and compare the heat of combustion of two different fuels, paraffin wax and ethanol, as the heat per gram of fuel consumed is calculated.

• Heat of Combustion: Magnesium (40 min.)

Determine the heat of reaction for the combustion of magnesium ribbon by using Hess’s Law.

GASES

• Boyle’s Law: Pressure-Volume Relationship in Gases (40 min.)

Determine the relationship between the pressure and volume of a confined gas.

• Pressure-Temperature Relationship in Gases (40 min.)

Determine what kind of mathematical relationship exists between the pressure and absolute temperature of a confined gas.

• Vapor Pressure of Liquids (40 min.)

Investigate the relationship between the vapor pressure of a liquid and its temperature. Then compare the vapor pressure of two different liquids, ethanol and methanol, at the same temperature.

SOLUTIONS

• Determining the Concentration of a Solution: Beer’s Law (40 min.)

Determine the concentration of an unknown nickel (II) sulfate solution (or a food coloring solution) using the colorimeter, Spectrophotometer 20 apparatus, or Spectro Vis and an absorbance vs. concentration plot of known concentrations (utilizing Beer’s Law).

• Effect of Temperature on Solubility of a Salt (40 min.)
  Study the effect of changing temperature on the amount of solute that will dissolve in a given amount of water. A graph of the temperature-solubility data, or solubility curve, will be plotted using the computer.

• Conductivity of Solutions: The Effect of Concentration (40 min.)

The influence of different concentrations of several ionic salts upon the conductivity of their solutions is determined using conductivity probes.

ACIDS AND BASES

• Household Acids and Bases (40 min.)

Use litmus and a computer interfaced pH sensor to determine the pH values of household substances such as vinegar, soda beverages, drain cleaner, lemon juice, ammonia and detergent.

• Acid Rain (40 min.)

Produce three gases, CO2, SO2 and NO2. Simulate the formation of acid rain by bubbling each of the gases into water and producing three acidic solutions. The acidity of the water will be monitored with a pH sensor.

• Titration Curves of Strong and Weak Acids and Bases (40 min.)

Observe differences in shapes of titration curves when various strengths of acids and bases are combined and learn about the function and selection of appropriate acid-base indicators.

• Acid-Base Titration (40 min.)

Titrate hydrochloric acid solution with a basic sodium hydroxide solution to determine the unknown concentration of HCl using a computer to monitor pH as the titration proceeds.

• Time-Released Vitamin C Tablets (40 min.)

Use a pH Sensor to monitor and compare the behavior of timed-release vitamin C tablets with regular vitamin C tablets when each is added to distilled water over an elapsed time.

• Acid Dissociation Constant, Determining Ka. (40 min.)

Experimentally determine the dissociation constant, Ka, for acetic acid, starting with solutions of different initial concentrations.

• The Buffer in Lemonade (40 min.)
  Use a pH Sensor to monitor pH as you titrate a given volume of a commercial brand of lemonade drink and an unbuffered solution of 0.010 M citric acid. Compare the results of the unbuffered solution with the lemonade buffer system.

• Determining the Phosphoric Acid Content in Soft Drinks (40 min.)
  Use a pH Sensor to monitor pH during the titration of phosphoric acid in a cola soft drink and use the titration equivalence point to determine the molarity of the phosphoric acid.

KINETICS

• Rate Law Determination of the Crystal Violet Reaction (40 min.)

Observe the reaction between crystal violet and sodium hydroxide to study the relationship between the concentration of crystal violet and the time elapsed during the reaction. Determine the order of the reaction, the rate constant and the half-life for the reaction.

• The Kinetics of a Bleach Reaction (40 min.)
  The objective of this experiment is to determine the rate law and order of a reaction between food coloring and commercial bleach based on your analysis of the graph of absorbance vs . time using a Vernier Spectrometer (SpectroVis).

CHROMATOGRAPHY AND SPECTROSCOPY

• What Alcohols are in the Mixtures? (40 min.)

Use the Gas Chromatograph (GC) apparatus to identify and separate alcohols in mixtures such as windshield washer fluid, rubbing alcohol and mouthwash.

• Identifying Organic Liquids Using Infrared Spectroscopy (40 min.)

Using the FTIR, students will look at the spectra of various unknown liquids. By comparing to a table of values, the functional groups present can be determined and the molecules can be identified.

• FTIR Fatty Acids (40 min.)

Using infrared (IR) spectroscopy, students will determine different types of fatty acids in foods samples such as Crisco shortening, butter, margarines and assorted oils that have trans fatty acids on the label.

• Testing the Effectiveness of Sunscreens (40 min.)

Using the UV-VIS Spectrophotometer, students compare the ability of various sunscreen brands or SPF values to protect against ultra-violet rays.

• Beet Lab (40 min.)

Using a UV-VIS Spectrophotometer, students will determine under which pH conditions a betalain from red beet can be used as a red-purple dye. They will also demonstrate that a single dye can be used to make different colors.

• Visible Spectra of Commercial Dyes (40 min.)
  In this experiment, you will use a Vernier Spectrometer (SpectroVis) to measure and analyze the visible light absorbance spectra of various samples of aqueous food dye mixtures such as soda and mouthwash over the 380 – 950 nm range and compare the spectra of the dyes to the spectra of various commercial products.

• Emission Spectra (40 min.)

In this experiment, students use a Vernier Spectrometer (SpectroVis) to measure the emission spectrum of helium, hydrogen, krypton and neon spectral tubes.

• Transmittance of Theatrical Lighting Filters (40 min.)

In this experiment, students use a Vernier Spectrometer (SpectroVis) to measure and analyze the visible light transmittance spectrum of various samples of theatrical lighting filters. Students will compare and contrast the spectra of lighting filters with the published information.

• Spectroscopy of Ice Pops (40 min.)

Using our new Vernier SpectroVis visible spectrophotometers, students can determine the visible absorbance spectra for each of the four commercially available food dyes. Then by running absorbance spectra for samples of the six Ice Pop flavors, students can determine which food dye or dyes are used in the Ice Pop. This lab is a very good introduction to spectrophotometry and mixing colors.

NUCLEAR CHEMISTRY

• Alpha, Beta, and Gamma (40 min.)

Use a radiation monitor to measure the absorption of alpha, beta and gamma radiation by air, paper and aluminum.

• Distance and Radiation (40 min.)

Use a counter to measure the radiation emitted by a gamma source as a function of distance

• Lifetime Measurement (40 min., 30 waiting time)

The radiation monitor is used to measure the decay constant and half life of barium-137 using a Cesium/Barium-137 Isogenerator.

• Radiation Shielding (40 min.)
  Use a radiation monitor to study how the radiation emitted by a beta source is absorbed by cardboard.
  
  

• Combined Radiation: Penetrating and Shielding Ability (40-80 min.)
  In this lab, students will use alpha, beta and gamma radiation sources and various shielding materials along with the Vernier Radiation Monitor to determine the penetrating and shielding abilities of materials.

   

The following components of the Chemistry Crime Scene can be completed over a period of 4-5 days. If a shorter time period is preferred, some components can be left out.

• Melting Point (25 min.)

Students use the Mel-Temp apparatus to analyze and identify white powders.

• Paper Chromatography (40 min.)
  The simple technique is used to analyze ink from a note found at the crime scene and compare it to ink from confiscated pens.

• Analysis of Fabrics (20 min.)

Students analyze fabric samples using both a fabric stain test and a burning test in order to determine the type of fabric, i.e. cotton, polyester, nylon, etc.

• Gas Chromatography (40 min.)

Students will separate and identify the type of alcohol present in unknown samples found at the crime scene and compare with data of their suspect samples.

• Infrared Spectroscopy (40 min.)
  The IR will be used to look at plastic film samples. Students will have some practice looking at wavenumbers and identifying functional groups. They will also compare to a database to identify the source of the plastic samples.

• Spectrophotometry (40 min.)
  Students will use the Spectronic 20 Genesys (Spec 20) to analyze Kool-Aid samples. This lab includes a recreation of events in which the students must carry out a serial dilution to create their own samples.

• CSI - Soil Testing (30 min.)
  Students will receive a crime scene soil sample in addition to soil samples associated with 6 suspects. Students will then perform four tests that should ensure matching the crime scene evidence with one or more of the suspects. The four tests are: Visible description, water absorption rate, pH and conductivity.

CRYOGENICS

• Demonstrates the effects of extreme cold using liquid nitrogen.

NANOTECHNOLOGY

• Gold Nanoparticle Synthesis and Analysis (40 min.)
  Students synthesize gold nanoparticles and explore their size-dependent properties by adding salt or sugar.

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