HONORS CHEMISTRY I

Core Lab Summaries

Revised Summer 2001

 

ACTIVITY 1: Milk Kaleidoscope

 

PURPOSE: To use the scientific method to observe, hypothesize, experiment, and collect data

 

SUMMARY: Students make observations, propose a hypothesis to explain those observations, devise an experiment to test that hypothesis, and then accept or revise the hypothesis based on evidence.

 

EQUIPMENT: Petri dish, dish detergent, hand soap, laundry detergent, whole milk, 1% milk, Half & Half, fruit juice, vegetable oil, toothpick, four different colors of food coloring

 

SAFETY: Glass petri dishes are fragile.

 

ACTIVITY 2: Separating Mixtures

 

PURPOSE: To separate two salts in solution by using solubility differences and filtration; determine the percentage of the two salts present.

 

SUMMARY: Students use the relationship between solubility and temperature for NaCl, KNO3, and Cu(NO3)2 to separate the chemicals and the determine the percent of each present. Students first learn the technique using the NaCl-KNO3 solution and then most devise their own experiment to separate the KNO3-Cu(NO3)2 solution.

 

EQUIPMENT: NaCl-KNO3 and KNO3-Cu(NO3)2 solutions, beakers, graduated cylinders, balance, burner equipment, filtration equipment

 

SAFETY: Goggles and aprons; open flame is used; glassware is fragile

 

ACTIVITY 3: Comparing Chemical and Physical Changes

 

PURPOSE: To distinguish chemical reactions from physical changes; to identify indicators that a reaction has occurred.

 

SUMMARY: Students conduct a series of procedures, observe the results, and determine how to distinguish chemical reactions from physical changes.

 

EQUIPMENT: Magnifying glass; test tubes, holder, and rack; burner apparatus; toothpicks; graduated cylinder; balance; crucible and tongs; pipet, Cu wire, CoCl2h6H2O, NaCl, and solutions of AgNO3, HCl, and NH3

 

SAFETY: Goggles and aprons; open flame is used; corrosive chemicals are used

 

ACTIVITY 4: Flame Test

 

PURPOSE: To understand how electrons make quantum leaps from one energy level to another

 

SUMMARY: Students observe characteristic colors produced by certain metallic ions when they are excited in the flame; explain what causes the colors, and identify an unknown ion by its flame test.

 

EQUIPMENT: Bunsen burner, wooden splints soaked in various metal chloride solutions.

 

SAFETY: Goggles and aprons; open flame is used; chemicals may be toxic if ingested

 

 

 




ACTIVITY 5: Periodic Relationships

 

PURPOSE: To understand how and why the elements are arranged in the Periodic Table

 

SUMMARY: Students first develop a classification scheme for a set of hardware. Then they classify several elements based on their atomic number, atomic radius, and first ionization number.

 

EQUIPMENT: Set of bolts, hex nuts, and wing nuts for each group, balance, ruler, chart of element properties.

 

SAFETY: No safety precautions are needed

 

ACTIVITY 6: Composition of Hydrates

 

PURPOSE: To determine the percent water in a hydrate and calculate the water of hydration.

 

SUMMARY: Students heat a known hydrate (CuSO4h5H2O) to dryness and calculate the ratio of water to hydrate. The procedure is repeated with an unknown hydrate (BaCl2h2H2O).

 

EQUIPMENT: CuSO4h5H2O, BaCl2h2H2O, Burner apparatus, beaker and tongs, watch glass, balance

 

SAFETY: Goggles and aprons; open flame is used; chemicals may be toxic if ingested

 

ACTIVITY 7: Research Project

 

PURPOSE: Use the scientific method to design and conduct a useful research project. Communicate results clearly and concisely.

 

SUMMARY: Students choose a question that is of interest to them, design and conduct an experiment to answer that question, write their findings in a scientific paper format, and then submit the project results to Science Fair or OJAS competition.

 

EQUIPMENT: Varies from project to project

 

SAFETY: Varies from project to project; ISEF rules and regulations apply

 

ACTIVITY 8: The Mole

 

PURPOSE: To develop an understanding of the mole concept and molar masses through an analogy with a model system.

 

SUMMARY: Students use relative masses of lima, pinto, lentil, black, and kidney beans to model relative atomic masses. Then they compare actual atomic masses in grams and relate those numbers to the mole concept.

 

EQUIPMENT: Bag of beans listed above, balance, beaker or cup, calculator

 

SAFETY: No safety precautions are needed

 

 

 

 

 

 

 

ACTIVITY 9: Types of Chemical Reactions

 

PURPOSE: To distinguish reactants from products,  observe and classify four types of chemical reactions: synthesis, decomposition, single displacement, and double displacement

 

SUMMARY: Students observe several chemical reactions, classify the type of reaction, and write the balanced equation representing the reaction.

 

EQUIPMENT: Mg; Ca(OH)2, HCl, and AgNO3 solutions; soda water; beakers; test tubes, holder, and rack; ring stand and clamp; crucible and cover; utility clamp; wooden splints; graduated cylinder; forceps

 

SAFETY: Goggles and aprons; open flame is used; chemicals may be toxic if ingested; hood should be used in solution preparation

 

ACTIVITY 10: FeCl2 or FeCl3?

 

PURPOSE: To apply the mole concept to chemical formulas

 

SUMMARY: Students react iron with CuCl2 in solution and determine if the product is FeCl2 or FeCl3 by using molar mass relationships.

 

EQUIPMENT: CuCl2, HCl, Fe nails, sandpaper, beaker, crucible tongs, balance, and drying oven

 

SAFETY: Goggles and aprons; chemicals may be toxic if ingested; oven is hot; hood should be used in solution preparation

 

ACTIVITY 11: Heating and Cooling Curves of Lauric Acid

 

PURPOSE: To observe and graph the effects of temperature on a pure substance during heating and cooling.

 

SUMMARY: Students heat lauric acid in a hot water bath until it is completely melted and the temperature rises several degrees. They also measure the temperature as the acid re-solidifies. The results are graphed.

 

EQUIPMENT: Test tube of lauric acid, hot water bath apparatus, thermometer

 

SAFETY: Goggles and aprons; open flame is used; avoid breathing lauric acid fumes.

 

ACTIVITY 12: Molar Volume of a Gas

 

PURPOSE: To determine theoretically and experimentally the volume of one mole of H2 at STP.

 

SUMMARY: Students react Mg with HCl in a gas burette, collect the gas, and calculate the molar volume converting to STP conditions.

 

EQUIPMENT: Gas burettes, stoppers, ring stand with utility clamp, thermometer, large beakers, graduated cylinders, 3M HCl, Mg ribbon, ruler

 

SAFETY: Goggles and aprons; corrosive chemical is used; glass burettes are fragile; hood should be used in solution preparation

 

 

 

 

 

ACTIVITY 13: Boiling Point Elevation and Molar Mass

 

PURPOSE: To relate the concentration of a solution to boiling-point elevation data.

 

SUMMARY: Students measure boiling point temperature for distilled water and NaCl, sucrose, MgSO4 solutions, and an unknown solution. Using Ætb and Kb to calculate molalities, they try to correctly identify the unknown.

 

EQUIPMENT: MgSO4h7H2O, NaCl, sucrose, flasks, balance, beaker tongs, burner apparatus, thermometer, ring stand and clamp, utility clamp, wire gauze

 

SAFETY: Goggles and aprons; chemicals may be toxic if ingested; glass flasks are fragile; open flames are used.

 

ACTIVITY 14: Equilibrium

 

PURPOSE: To observe color changes in solutions as indications of shifts in equilibrium and explain those shifts by applying Le Chatelier’s Principle.

 

SUMMARY: Students note the color of several chemical reactions and then observe the effect on products when more reactants are added. They explain the changes in terms of Le Chatelier’s Principle.

 

EQUIPMENT: 24-well microplate; test tube; pipets; CuSO4, CH3COOH, FeCl3, KSCN, HCl, and NH3 solutions; Fe(NO3)3, K2HPO4, KCl, CH3CONa, and NH4SCN.

 

SAFETY: Goggles and aprons; chemicals may be toxic if ingested; hood should be used in solution preparation

 

ACTIVITY 15: Acid-Base Titration

 

PURPOSE: To determine the molarity of NaOH by titrating it with a standard HCl solution.

 

SUMMARY: Students perform a classic acid-base titration.

 

EQUIPMENT: Burettes and clamps, ring stand, flask, phth,

 

SAFETY: Goggles and aprons; chemicals are corrosive; glass burettes are fragile; hood should be used in solution preparation

 

ACTIVITY 16: Rates of Reaction

 

PURPOSE: To observe the effects of varied concentrations and temperatures on the rate of chemical reactions.

 

SUMMARY: Students perform the classic clock iodine reaction using different concentrations of the solutions and different temperatures. They measure the time it takes for the reaction to occur under the differing conditions.

 

EQUIPMENT: Liquid starch, I2, H2SO4, beakers, ice, hot plate, thermometer, stop watch

 

SAFETY: Goggles and aprons; glassware is fragile