Chapter 5 Lecture - Gases

These flashcards cover key vocabulary from the Chapter 5 lecture on Gases, including characteristics, pressure definitions and units, gas laws, standard conditions, and the Ideal Gas Law and its applications.

Gases Characteristics

Conform to the shape of container and fill it, particles are far apart and move randomly, volume affected by pressure and temperature, flow freely, have low densities, and form solutions in any proportion.

Gas Pressure

The force of the collisions of gas molecules with the walls of the container, calculated as force/area.

Barometer

A device used to measure atmospheric pressure.

Manometer

A device used to measure the pressure of a gas in an experiment.

Pascal (Pa)

The SI derived unit of pressure, equal to 1 N/m^2.

Standard Atmosphere (atm)

The average atmospheric pressure measured at sea level at 0 ext{\degree}C; 1 atm = 101.325 kPa = 101,325 Pa.

Millimeter of mercury (mmHg) or torr

Units of pressure; 1 atm = 760 mmHg = 760 torr.

Bar

A unit of pressure; 1 bar = 100 kPa = 100,000 Pa.

psi

Pounds per square inch (lbs/in^2), a unit of pressure; 14.7 psi = 1 atm.

Four Variables Describing Gases

Pressure (P), Temperature (T), Volume (V), and Amount (n); these are interdependent.

Gas Laws

Mathematical expressions that describe the effect of one variable on another while holding the other two constant.

Ideal Gases

Hypothetical gases that have a linear relationship among amount (n), volume (V), pressure (P), and temperature (T), assuming no ideal gas exists but N2, O2, H2, and noble gases are nearly ideal at ordinary conditions.

Boyle's Law

P1V1 = P2V2

Charles's Law

V1/T1 = V2/T2

Gay Lussac's Law

P1/T1 = P2/T2

Combined Gas Law

P1V1/T1 = P2V2/T2

Avogadro's Law

V1/n1 = V2/n2

Standard Temperature (STP)

0 ext{\degree}C or 273 K.

Standard Pressure (STP)

1 atm or 760 mmHg.

Standard Molar Volume (STP)

The volume occupied by 1 mole of gas at STP, which is 22.4 L.

Ideal Gas Law

PV = nRT

Ideal Gas Constant (R)

A proportionality constant in the Ideal Gas Law.

Value of Ideal Gas Constant (R)

R = 0.0821 atm
otin L / (mol
otin K)

Density of a Gas

Derived from the Ideal Gas Law as D = P \cdot MM/(RT), where MM is molar mass.

Molar Mass of a Gas

Derived from the Ideal Gas Law as MM = mRT/(PV).

Partial Pressure

The pressure exerted by an individual gas in a mixture, behaving as if it were the only gas present.

Dalton's Law of Partial Pressures

In a mixture of non-reacting gases, the total pressure is the sum of the partial pressures of the individual gases.