Gas Laws

Question 1

Absolute Pressure

Answer 1

The total pressure measured relative to a vaccum, includes atmospheric pressure.
Formula:
Absolute = Gauge + Atmospheric

Question 2

Atmospheric Pressure

Answer 2

The weight of the atmosphere pressing down on a surface. (~101.325kPa or 1 atm)

Question 3

Barometer

Answer 3

Instrument used to measure atmospheric pressure.

Question 4

Manometer

Answer 4

Instrument used to measure the pressure of a gas trapped in a container.

Question 5

Boyle’s Law (explain + formula)

Answer 5

States that when V decreases, collisions increase and P increases (constant temperature).
P1V1=P2V2

Question 6

Charles’ Law (explain + formula)

Answer 6

Volume (V) and Temperature (T) are directly related (constant pressure)
V1/T1 = V2/T2

Question 7

Combined Gas Law

Answer 7

Combines Boyle’s, Charles’ and Gay-Lussac’s laws. Formula: P1V1/T1 = P2V2/T2

Question 8

Gay-Lussac’s Law (formula)

Answer 8

Pressure is directly related to temperature. Formula: P1/T1 = P2/T2

Question 9

Ideal Gas
(Question 17 on exam review)

Answer 9

Hypothetical gas that follows all gas laws perfectly; no IMFs or volume.
Formula: PV = nRT

Question 10

Real Gas

Answer 10

Gases that deviate from ideal gas behaviour under high/low pressure

Question 11

Dalton’s Law of Partial Pressure

Answer 11

Total pressure of a gas mixture equals the sum of the pressures of each gas. Formula: Ptotal = P1 + P2 +…

Question 12

Relative Humidity

Answer 12

The percentage of moisture in the air compared to the max it can hold at that temperature

Question 13

Relative Pressure (Gauge Pressure)

Answer 13

Pressure of a system measured relative to atmospheric pressure. Formula: Gauge = Absolute - Atmospheric

Question 14

Temperature

Answer 14

A measure of the average kinetic energy of particles in a substance

Question 15

Kelvin Temperature Scale

Answer 15

Absolute temperature scale used in gas laws. Conversion: T(K) = T (°C) + 273.15

Question 16

Melting Point

Answer 16

Temperature at which a solid changes to a liquid under standard pressure

Question 17

Boiling Point

Answer 17

Temperature at which a liquid’s vapor pressure equals atmospheric pressure

Question 18

Pressure

Answer 18

Force applied perpendicular to a surface per unit area. Measure of force exerted by particles colliding with container walls

Question 19

STP + SATP

Answer 19

Standard Temp + Pressure
Standard Ambient Temp + Pressure

Question 20

What are the 4 units for pressure?

Answer 20

Atm, Torr, mmHg, kPa

Question 21

Five postulates of the kinetic molecular theory
(Question 15 on exam review)

Answer 21

• All matter consists of tiny particles (atoms or molecules) in constant random motion
• Particles have negligible volume compared to the space between them
• The particles have perfectly elastic collisions (no energy is lost during collisions)
• There are no attractive or repulsive forces between the particles
• The average kinetic energy of the particles is directly proportional to the absolute temperature