160 likes | 474 Views
Plop! Plop! Fizz! Fizz! Oh, the things chemistry teachers can do with AlkaSeltzer !. Patricia Mason, PAEMST 2003 Delphi Community High School masonp@delphi.k12.in.us. Judith Flint Baumwirt Granada Hills Charter High School jbaumwirt@ghchs.com.
E N D
Plop! Plop! Fizz! Fizz!Oh, the things chemistry teacherscan do with AlkaSeltzer! Patricia Mason, PAEMST 2003 Delphi Community High School masonp@delphi.k12.in.us Judith Flint BaumwirtGranada Hills Charter High School jbaumwirt@ghchs.com July 2005, ChemEd Conference, UBC, Vancouver, Canada
Experiments and Activities • Alka Seltzer Rainbow - ChemFax Demonstration (provided by Flinn Scientific) • Alka Seltzer Rockets • Buffering Ability of Alka Seltzer Tablets • Buffer Balancing Acts - ChemFax Demonstration (provided by Flinn Scientific) • Common Ion Effect on the Solubility ofAlka Seltzer
Experiments and Activities • Change in pH and Temperature as a Reaction Occurs • Differentiating Liquids • Decomposition of Effervescent Tablets • Decomposition of Effervescent Tablets with Sample Data Analysis/Results • Density Challenge • Does a Gas Have Mass?
Experiments and Activities • Effect of Particle Size on Rate of Reaction Demonstration • Effect of pH on rate of reaction • Effect of Temperature on Rate of Reaction Demonstration • Rate of Reaction Lab - Combined Activities for Students • Equilibrium and Rate Determining Step demonstrations
Experiments and Activities • Micro Popper (provided by Flinn Scientific) • Quantitative Determination of Sodium Bicarbonate in Alka Seltzer • Second Quarter Laboratory Evaluation: Analysis of Alka Seltzer(provided by Flinn Scientific) • What Chemists Do: Identification and Analysis - White Powder Identification
Alka-Seltzer Rockets • Factors affecting the rates of solution • It is important to break tablets evenly into four quarters • Only Fuji canisters provide a good seal(lid fits securely inside the canister) • Inverted in the launcher • Can be used test variables
Effect of Temperature on Rate of Reaction Teacher demonstration Student activity Effect of Particle Size on Rate of Reaction Whole tablet Broken in half Quartered Coarsely ground Finely ground Factors Affecting Rate of Reaction
Effect of pH on Rate of Reaction • Complicated set-up • Glass work done by teacher saves time • Solutions available of various pH • Each group uses water plus 2 others • Water displacement technique • Plotting data and analysis • Comparison of rates with pH
Common Ion Effect • Can be used as a discrepant event • Why do the tablets dissolve at different rates and in varying amounts?
Must use probeware for pH Temperature Tablets are added to room temperature water Data taken for 5 minutes Variables can be changed Number of tablets Division of tablets Amount of water Amount of agitation Monitoring Changes in pH and Temperature as Reaction Occurs
Macro-Demonstration Burets HCl and NaOH Universal indicator HCl with water HCl with tablet NaOH with tablet NaOH with water Can also use pH probes Micro-Activity Broken tablets (0.15g to 0.20 g samples) Well-plates Universal indicator Calibrate the micro-pipettes for drops Buffering Ability of Alka-Seltzer Tablets
Does a Gas Have Mass? • Can be used initially for introduction to Chemistry • Can be used to demonstrate conservation of mass • When a gas is produced is mass lost? • Baggie provides a closed system
Differentiating Liquids Lab • Good introductory lab activity • Properties of Liquids • Viscosity • Density • Solubility • Detailed data recording and evaluation • Inquiry section, if time permits
Equilibrium and RateDetermining Step Demo • An entertaining student-centered activity • Shows the progress of a reaction from reactants to a mixture of reactants and products • Can visually recognize that the reaction is favored in the decompositon direction • The “Slow step” is obvious in this demonstration
What Chemists Do – A Beginning Analysis Lab • This is a good application of inquiry and the scientific method. • May be useful as a beginning lab on analysis • Students have three unknowns to determine so the lab requires some extended prep time.
AP Chemistry Stoichiometry Calculations Limiting Reactant Graphing Acid-base Solutions Decomposition Quantitative Determination of Sodium Bicarbonate