Gas Properties Quiz: Thermodynamics and Behavior

Gas Properties and Behavior

• A sample of gas in a rigid cylinder with a movable piston has a constant pressure, and if the Kelvin temperature doubles, the volume of the gas also doubles.
• A gas takes the shape and volume of its container and has neither a definite shape nor a definite volume.

Gas Temperature and Energy

• Temperature is a measure of the average kinetic energy of particles in a sample of matter.
• A sample of gas confined in a sealed container has a definite temperature, such as 298 K or 267 K.

Ideal Gas Properties

• According to the kinetic molecular theory, the molecules of an ideal gas have no attraction for each other, have significant volume, and move in random, constant, straight-line motion.
• Standard pressure is equal to 1 atm or 101 kPa.

Gas Diffusion and Volume

• Given the same conditions of temperature and pressure, hydrogen (H2) will diffuse most rapidly among the noble gases.
• A sample of H2(g) and a sample of N2(g) at STP contain the same number of molecules, meaning they have the same volume but different masses.

Pressure and Volume Relationships

• As the pressure on a sample of gas increases at constant temperature, the volume of the gas decreases.
• As the temperature of a sample of gas increases at constant pressure, the volume of the gas sample increases.
• If the Kelvin temperature of a gas sample doubles while the pressure is halved, the volume of the gas will increase by four times.

Gas Mixtures and Partial Pressure

• The pressure of a mixture of gases is the sum of the partial pressures of each gas.
• The partial pressure of a gas in a mixture is proportional to its mole fraction in the mixture.

Graphical Representations

• The graph that best represents how the volume of a given mass of a gas varies with the pressure exerted on it at constant temperature is a hyperbola.
• The graph that best represents how the volume of a given mass of a gas varies with the Kelvin temperature at constant pressure is a straight line with a positive slope.