Flashcards: Kinetic Theory and Gas Behavior — 62 cards

What does the kinetic theory of gases explain?

The similar behavior of gases by relating properties to particle motion and kinetic energy.

What defines an ideal gas in terms of particle volume?

Its particles occupy negligible volume.

What forces do particles of an ideal gas exert on each other?

No attractive forces.

What defines a phase change in a substance?

A physical transformation changing appearance or phase without changing nature.

Which four phases of matter are discussed?

Solid, liquid, gaseous, and plasma.

What particle movement occurs in all phases of matter?

Vibration.

In which phases does particle rotation occur?

Liquids and gases.

Where is particle translation strongest and where is it weaker?

Strongest in gases and weaker in liquids.

What shape and volume do solids have?

Determined shape and volume.

What shape and volume do gases have?

Indefinite shape and volume.

What shape and volume do liquids have?

Determined volume but indefinite shape.

Why are solids almost incompressible?

Because their particles are very close together and strongly bound.

Why are gases highly compressible?

Because their particles are very far apart.

How do liquid particles move to allow flow and shape change?

They vibrate, rotate, and translate slightly.

How do gas particles move and spread?

By strong translation along random linear paths in every direction.

What is kinetic energy in terms of object motion?

Energy an object has due to its motion.

What is the formula for the kinetic energy of a gas particle?

$E_c = \frac{1}{2}mv^2$

In which units must mass and speed be measured for kinetic energy formula?

Mass in kilograms and speed in meters per second.

What happens to average kinetic energy when gas temperature increases?

It increases.

What changes occur in gas particle speeds as temperature rises?

Most probable and average speeds increase.

How does the speed distribution curve shift when temperature increases?

It shifts toward higher speeds.

What does the kinetic theory describe about gases?

An ideal gas enclosed in an undeformable container.

Why are gas particles considered point-like in kinetic theory?

Because their size is negligible compared with the container's volume.

How do gas particles move according to kinetic theory?

Continuously in straight lines in all directions.

What type of collisions do gas particles undergo?

Perfectly elastic collisions without energy loss.

What forces do gas particles exert on each other between collisions?

No attractive or repulsive forces.

How does average kinetic energy of gas particles vary with gas type at a given temperature?

It is the same for all gases regardless of their nature.

What is compressibility in gases?

The ability of a gas to decrease in volume when a force is applied.

How does expansion of a gas behave in accessible space?

It spreads indefinitely to fill all accessible space.

What factor affects gas expansion besides filling space?

Atmospheric pressure.

What causes diffusion of gases in a container?

Random particle motion.

What is the result of diffusion in a gas container?

Particles become uniformly distributed.

What is effusion in gases?

Passage of gas through a small opening in a wall.

Give an example of effusion involving helium.

Helium escaping through pores in a balloon membrane.

What formula expresses Graham's law relating gas speeds and molar masses?

$\frac{v_1}{v_2}=\sqrt{\frac{M_2}{M_1}}$

Under identical conditions, which gas diffuses faster: lower or higher molar mass?

A gas with lower molar mass diffuses faster.

What is gas pressure in terms of force and area?

Force exerted by gas particles on a surface per unit area.

What is the formula to calculate pressure?

$P=\frac{F}{A}$ where P is pressure, F is force, and A is area.

What causes gas pressure inside a container?

Particle collisions with container walls.

How does the number of collisions affect gas pressure?

More collisions per unit area produce greater pressure.

What is atmospheric pressure?

Force exerted by air equivalent to the weight of the air column above a surface.

Why is atmospheric pressure higher near sea level?

Air is denser near the ground and collisions are more frequent.

How does atmospheric pressure change with altitude?

It decreases rapidly with altitude.

How does a closed-end manometer measure gas pressure?

By the mercury height difference directly.

What must an open-end manometer account for when measuring gas pressure?

Atmospheric pressure.

What is the formula for gas pressure in a closed-end manometer?

$P_{gas}=h$

When gas pressure exceeds atmospheric pressure, how is $P_{gas}$ calculated in an open-end manometer?

$P_{gas}=P_{atm}+h$

When gas pressure is lower than atmospheric pressure, how is $P_{gas}$ calculated in an open-end manometer?

$P_{gas}=P_{atm}-h$

What is the normal atmospheric pressure in kilopascals?

101.3 kPa

What is the normal atmospheric pressure in millimeters of mercury?

760 mm Hg

When was the kinetic theory of gases developed?

During the eighteenth century.

How was the kinetic theory of gases developed?

From observations made by numerous scientists.

What path does a particle follow during translation?

A straight line from one collision to the next.

What compressibility corresponds to solids, liquids, and gases?

Almost no compressibility for solids and liquids, strong compressibility for gases.

Why do gas particles have different kinetic energies at the same temperature?

Because collisions transfer kinetic energy between particles.

Which scientist explained kinetic energy variation among gas particles?

James Clerk Maxwell.

Why do lighter gas particles diffuse faster at the same temperature?

Because they move faster.

What are the diffusion speeds of nitrogen and oxygen at the same temperature using Graham's law?

Nitrogen diffuses at 0.098 m/s and oxygen at 0.092 m/s.

What is the approximate molar mass of a gas effusing at 0.077 m/s compared to helium at 0.256 m/s?

About 44 g/mol.

Which gas could have a molar mass of about 44 g/mol and effuses slower than helium?

Carbon dioxide.

Who designed the barometer to measure atmospheric pressure and when?

Evangelista Torricelli in 1643.

Which instrument measures atmospheric pressure?

A barometer.