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Stoichiometry and Moles
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Stoichiometry and Moles—Demonstration Kits
Mole Ratio—Chemical Demonstration Kit
By: The Flinn Staff
Determine the balanced chemical equation when you
only know the formulas of the reactants using the method of continuous variation. Mix solutions of sodium hypochlorite and sodium thiosulfate in various volume and mole ratios, with the total number of moles of reactants held constant. The amount of heat released in the exothermic reaction is directly proportional to the amount of product formed. The maximum temperature change is produced at the optimum mole ratio of reactants. Students plot temperature versus the volume ratio to deter- mine the mole ratio and identify the products of the overall reaction. Great critical-thinking demonstration!
Concepts: Stoichiometry, mole ratio, oxidation–reduction, heat of reaction. Time Required: 20 minutes
Chemicals Provided: Sodium hypochlorite solution, sodium thiosul- fate solution, polystyrene cups.
Note: Perform this demonstration in a fume hood or well-ventilated lab.
Stoichiometry Balloon Races— Chemical Demonstration Kit By: The Flinn Staff
If a little is good, more is better, right? Not necessarily! In a chemi- cal reaction, the amount of product that can be obtained depends on the mole ratio of reactants. If the moles of one reactant are limited, it does not matter how much of a second reactant is added, the amount of product will not change. If your students are struggling with the idea of limiting and excess reactants, you need this demonstration. Compare the size of balloons as they are inflated with carbon dioxide from the reaction of varying amounts of sodium bicarbonate with a constant amount of acetic acid. Watch as your students immediately identify the limiting and excess reactants in the great stoichiometry balloon race. Demonstration Notes included.
Concepts: Stoichiometry, mole ratio, limiting reactant, excess reactant. Time Required: 20 minutes
Chemicals Provided: Acetic acid solution, sodium bicarbonate.
See free video at flinnsci.com.
Stoichiometry and Solubility—
Mole Ratios and Chemical Formulas—
Chemical Demonstration Kit
By: The Flinn Staff
Teach students about chemical formulas, balanced chemical equations, and mole ratios with this unique “continuous variation” demonstration. Mix two solutions in various proportions and measure the volume of precipitate that forms in each mixture. Why do different ratios of liquids produce different amounts of precipitate? Which ratio will give the most precipitate? There’s a simple answer but a powerful lesson—the maximum amount of precipitate will form when the ratio of the two solutions corresponds to the optimum mole ratio for the reactants. Chemicals are provided for two series of reactions, copper(II) chloride with trisodium phosphate and iron(III) nitrate with sodium hydroxide. Bright colorful solutions produce contrasting color precipitates that stand out and are easy to see. Demonstration Notes included. Concepts: Stoichiometry, mole ratio, double replacement reaction, solubility rules.
Time Required: 30 minutes
Chemicals Provided: Copper(II) chloride solution, iron(III) nitrate solution, sodium hydroxide solution, trisodium phosphate solution.
See free video at flinnsci.com.
Mole Ratio—Chemical Demonstration Kit AP7360
Catalog No.
Description
Price/Each
AP7360
Mole Ratio—Chemical Demonstration Kit
$28.25
Catalog No.
Description
Price/Each
AP6444
Stoichiometry Balloon Races— Chemical Demonstration Kit
$31.80
Stoichiometry Balloon Races—Chemical Demonstration Kit AP6444
Stoichiometry and Solubility—Mole Ratios and Chemical Formulas— Chemical Demonstration Kit
AP6443
Catalog No.
Description
Price/Each
AP6443
Stoichiometry and Solubility—
Mole Ratios and Chemical Formulas— Chemical Demonstration Kit
$51.65
STOICHIOMETRY AND MOLES—DEMONSTRATION KITS continued on next page.