Gas Laws — Exploring the Behavior of Gases
9 experiments
Gas law experiments verify the mathematical relationships between pressure, volume, temperature, and amount of gas. From Boyle's law (P inversely proportional to V at constant T) to the ideal gas law (PV = nRT), these experiments connect macroscopic measurements to the kinetic molecular theory of gases, building intuition for thermodynamics and physical chemistry.
Learning Objectives
Verify Boyle's, Charles's, and Gay-Lussac's laws experimentally. Determine molar mass of a gas using the ideal gas equation. Measure gas production rates and relate them to reaction kinetics. Understand deviations from ideal behavior and the van der Waals equation.
Key Techniques
Collect gases over water using an inverted graduated cylinder (water displacement method). Use pressure sensors and syringes to verify Boyle's law. Measure gas volume at different temperatures using a gas syringe or sealed flask with a manometer. Correct for water vapor pressure when collecting gases over water.
Equipment Overview
Required: gas syringes, manometers, pneumatic trough, graduated cylinders, thermometers, pressure sensors. Digital sensors connected to data loggers allow real-time PV and VT plotting. Eudiometer tubes provide precise gas volume measurements.
Boyle's Law Verification
Demonstrating the inverse relationship between pressure and volume
Verify Boyle's law (P1V1 = P2V2) by measuring the volume of a trapped gas at different pressures.
Cartesian Diver
Demonstrating gas compressibility and Boyle's law
Build a Cartesian diver to demonstrate gas compressibility and the relationship between pressure and buoyancy.
Charles's Law with a Balloon
Measuring volume changes of a gas with temperature
Demonstrate Charles's law by measuring the circumference of an air-filled balloon at different temperatures.
CO₂ and Limewater Test
Detecting carbon dioxide with calcium hydroxide
Generate carbon dioxide gas from a carbonate-acid reaction and confirm its identity using the limewater test.
Diffusion Rate Comparison (Graham's Law)
Comparing diffusion rates of HCl and NH₃ gases
Verify Graham's law of diffusion by comparing the rates at which HCl and NH₃ gases travel through a glass tube.
Gas Stoichiometry with Magnesium
Calculating molar volume by reacting Mg with HCl
Determine the molar volume of hydrogen gas at room conditions by reacting a known mass of magnesium ribbon with excess …
Hydrogen Gas Collection
Generating and collecting hydrogen from zinc and acid
Generate hydrogen gas from the reaction of zinc with hydrochloric acid and collect it by water displacement.
Molar Volume of a Gas at STP
Experimentally determining 22.4 L/mol using butane
Determine the molar volume of butane gas at STP by measuring the mass and volume of gas released from a …
Vapor Pressure and Boiling Point
Measuring how vapor pressure changes with temperature
Measure the vapor pressure of water at different temperatures and verify the Clausius-Clapeyron equation.