GenChem7 (The Gas Phase)

Question 1

Name 3 ways that gas pressures are expressed in units

Answer 1

1 atm=760 mm Hg = 760 torr

Question 2

What is STP

Answer 2

1 atm

0° C, or 273 K

Question 3

What is the condition of standard conditions?

Answer 3

25°C or 298K

Question 4

A hypothetical gas whose molecules have no IM forces and occupy no volume.

Answer 4

Ideal Gas

Question 5

What is the equation for the Ideal Gas Law

Answer 5

PV=nRT

Question 6

How much volume does 1 mole of gas have, regardless of what molecule it is?

Answer 6

22.4 L

Question 7

What are the equations for density of a gas substance?

Answer 7

d=m/v=P*(MM)/RT

Question 8

What equations relate changes in the temperature, pressure, and volume of a gas?

Answer 8

(P1V1)/T1 = (P2V2)/T2

Question 9

Set up the equations for the density of HCL gas at 2atm and 45°C

Answer 9

22.4L/mol * (1atm/2atm) *(318K/273K) = 13.0L mol

d= (36g/mol)/(13.0L/mol)= 2.77 g/L

Question 10

What is the molar mass of a 2L sample of a gas that weighs 8g at 15°C and 1.5atm?

Answer 10

d=8g/2L at 15°C and 1.5 atm

V(stp)= 2L * (273K/288K)(1.5atm.1atm) = 2.84 L

8g/2.84L = 2.82g/L at STP

2.82g/L * 22.4L/mol = 63.2 g/mol

Question 11

Under what conditions do gases not behave ideally?

What property causes this behavior?

Answer 11

Extremely high pressure
Low temperature (condensation)

IM forces become stronger as molecules are closer together

Question 12

What is the equation for the partial pressure of a gas in a mixture?

Answer 12

Pa = P(total) * (moles of a)/(total moles)

Question 13

Part of kinetic molecular theory of gases,

Gases are made up of particles whose volumes are ____ compared to the container volume

Answer 13

Negligible

Question 14

Part of kinetic molecular theory of gases,

Gas atoms or molecules exhibit no _____ attractions or repulsions

Answer 14

Gas atoms or molecules exhibit no intermolecular attractions or repulsions

Question 15

Part of kinetic molecular theory of gases,

Gas particles are in continuous __________, undergoing collisions with other particles and the container walls

Answer 15

Random Motion

Question 16

Part of kinetic molecular theory of gases,

Collision between any two gas particles are ____, meaning that there is no overall gain or loss of energy

Answer 16

Elastic

Question 17

Part of kinetic molecular theory of gases,

The average kinetic energy of gas particles is proportional to the _______ of the gas, and is the same for all gases at a given ______

Answer 17

Temperature

Question 18

What are the equations for the average kinetic energy of gases?

Answer 18

KE=1/2mv^2 = 3/2kT

T is the absolute temperature

Question 19

This occurs when gas molecules diffuse through a mixture

Do light or heavy gas molecules diffuse more quickly?

Answer 19

Diffusion

Light molecules because of average kinetic energy theory

Question 20

The equation for the rates at which two gases diffuse and effuse

Answer 20

r1/r2 = sqrt(MM2/MM1)

Question 21

The flow of gas particles under pressure from one compartment to another through a small opening

Answer 21

Effusion.