Conservation of Mass and Buoyancy - Student Laboratory Kit

By: The Flinn Staff


In a chemical reaction, matter is neither created nor destroyed, except in this apparent contradictory experiment! Students will understand what is really measured when we “weigh” something on a balance.

Students first conduct an experiment to verify the law of conservation of mass in a chemical reaction. They then perform a second experiment in which the product gases are supported by buoyant forces in air. Air acts as a fluid and so the final mixture weighs less than the original. Because a balance actually weighs objects and converts this to mass readings, the apparent mass discrepancy really helps students understand the difference between "weighing" and "massing." Kit includes chemicals and equipment for 15 complete experimental setups, along with reproducible student handouts, detailed background information, and complete Teacher Notes with sample data and answers to all questions.

Complete for 30 students working in pairs. Requires a balance with sensitivity of at least 0.01-g.