In this lab experience, students carry out an investigation to determine the empirical formula of an unknown, binary compound. Students come to understand that the formula of a compound that can be decomposed into smaller elements by heating, is subject to empirical formula determination by mass loss methods. They understand this in the context of the law of conservation of mass. Students gain familiarity with calculations that involve the mole and mass percents.
Safety:
Remind students that the unknown compounds are toxic if swallowed and harmful if inhaled. Students should avoid breathing dust or fumes, should wear chemical splash goggles, chemical-resistant gloves, and a chemical-resistant apron. Students should wash hands thoroughly with soap and water before leaving the laboratory. Remind students to handle the hot crucible and its lid only with tongs. They should not touch the crucible with fingers or hands.
Materials Included in Kit
Consumable:
Barium chloride dihydrate, 75 g
Labels, 20
Non-Consumable:
Vials with snap-on caps, 10
Additional Materials Required Bunsen Burner, Adjustable, Natural Gas, 10
Crucible, Porcelain, High Form, with Cover, Flinn, 15-mL, 10
Crucible Tongs, 10
Flinn Scientific Electronic Balance, 120 x 0.001-g, 10
Support Stand, Economy Choice, 10
Wire Gauze Squares, with Ceramic Centers, 4″ × 4″, 10
Triangle, Pipe Stem, ", 10
1-800-452-1261
