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Stoichiometry and Moles
79
Stoichiometry and Moles—Laboratory Kits,
continued
Determining a Balanced Chemical Equation—Student Laboratory Kit By: The Flinn Staff
Stoichiometry! A word as strange to some students as the concept it defines. When chemical formulas are known, it is relatively easy to determine the mole ratios. When formulas are not known, students must apply experimentation to solve for these ratios. This experiment uses the method of continuous variation. First, solutions of the reactants are prepared with known concentrations. Solutions are then mixed a number of times using different volume ratios of reactants. Third, the heat liber- ated is measured. Students use the data to graph the mole ratio versus change in temperature. The intersection of the lines drawn through the ascending and descending data points gives the correct mole ratio for the reaction. Includes Instructor’s Notes and all chemicals and consumable supplies needed to perform the lab. Complete for 30 students working in pairs. Perform this experiment in a fume hood or well-ventilated lab.
Percent Composition—Calcium Magnesium Acetate—
Student Laboratory Kit
By: The Flinn Staff
A real-world application for a fundamental concept—percent composi- tion! Calcium magnesium acetate (CMA) is sold commercially as a “green” chemical deicer. It is less corrosive than salt for melting ice and protects delicate pet paws. Determine the percent composition of calcium versus magnesium acetate in CMA using a simple three-step process. Titrate with EDTA to determine total calcium and magnesium content, precipitate calcium ions with ammonium oxalate, and then carry out a second EDTA titration on the filtrate to measure the amount of magne- sium. Quantitative lab helps develop good lab skills and provides relevant experience for calculating number of moles, molar mass, and percent composition. Includes reproducible student handouts, detailed background information, complete Instructor’s Notes with sample data and answers to all questions, and all necessary chemicals and consumable supplies.
Complete for 30 students working in pairs. Burets are required and available separately.
Determining the Stoichiometry of Chemical Reactions—Classic General Chemistry Experiment See page 26.
Quantitative Determination of Barium—
Student Laboratory Kit
By: The Flinn Staff
This experiment is a very straightforward introduction to quantitative determinations. Students are given a mixture of barium nitrate and sodium nitrate salts. A portion of the sample is weighed and dissolved in water. Sulfuric acid is added to the solution and the barium is precipi- tated as barium sulfate. The students filter the precipitate, using ashless filter paper. The filter paper is burned away from the barium sulfate in a crucible. The crucible and dry barium sulfate are then weighed. The students use this data to calculate the percent of barium nitrate in the original sample. Students will gain experience in gravimetric analysis and precipitation techniques. Includes reproducible student procedure, complete Instructor’s Notes with sample data and answers to questions, and all the chemicals needed to perform the lab.
Complete for 24 students working in pairs. Super Value Kit is complete for 5 classes of 24 students working in pairs.
Determining a Balanced Chemical Equation—Student Laboratory Kit AP7393
Catalog No.
Description
Price/Each
AP7393
Determining a Balanced Chemical Equation— Student Laboratory Kit
$44.05
Catalog No.
Description
Price/Each
AP7502
Percent Composition—Calcium Magnesium Acetate—Student Laboratory Kit
$31.65
GP1087
Buret, Flint Glass with PTFE Stopcock, 50 mL
74.95
Percent Composition—Calcium Magnesium Acetate— Student Laboratory Kit
AP7502
Quantitative Determination of Barium—Student Laboratory Kit AP8834
Catalog No.
Description
Price/Each
AP8834
Quantitative Determination of Barium— Student Laboratory Kit
$24.20
AP7579
Quantitative Determination of Barium— Super Value Laboratory Kit
51.75
STOICHIOMETRY AND MOLES—LABORATORY KITS continued on next page.