Kinetic energy of gasses(feels incomplete)

Question 1

What are the macroscopic properties of matter?

Answer 1

Mass, density, pressure, temperature, volume, phase

Question 2

What do models show in kinetic theory?

Answer 2

How microscopic properties determine macroscopic properties

Question 3

What is an ideal gas?

Answer 3

Simplest gas model with infinitely small point particles, no intermolecular forces between moelcules

Question 4

What are the state variables of a substance?

Answer 4

Pressure (p), volume (V), temperature (T), amount (m or n)

Question 5

What is the ideal gas equation with moles?

Answer 5

p V = n R T. (R= ideal gas constant)

Question 6

What is the ideal gas equation with molecules?

Answer 6

p V = N k T

Question 7

How is number of moles (n) calculated?

Answer 7

n = m_total / M or n = N / N_A

Question 8

What is molar mass (M)?

Answer 8

Mass per mole of a substance

Question 9

How is density (ρ) expressed for an ideal gas?

Answer 9

ρ = p M / R T

Question 10

What equation applies for constant moles?

Answer 10

p1 V1 / T1 = p2 V2 / T2

Question 11

What is an equation of state?

Answer 11

Relation between p, V, T for a substance in equilibrium

Question 12

What happens to pressure if volume decreases (T, n constant)?

Answer 12

Pressure increases

Question 13

What is the average translational kinetic energy of a gas molecule?

Answer 13

K = (3/2) k T

Question 14

What is the total kinetic energy of 1 mole of gas?

Answer 14

K_tr = (3/2) n R T

Question 15

What is the rms speed (v_rms) of gas molecules?

Answer 15

v_rms = sqrt(3 R T / M) or sqrt(3 k T / m)

Question 16

What does the Maxwell-Boltzmann distribution describe?

Answer 16

Distribution of molecular speeds in an ideal gas

Question 17

What is C_V for monatomic vs diatomic gases and why?

Answer 17

Monatomic: (3/2) R; Diatomic: (5/2) R; each degree of freedom gets (1/2) k T

Question 18

What does a phase diagram show?

Answer 18

Conditions for phase equilibrium (p vs T)

Question 19

What is the triple point?

Answer 19

Where solid, liquid, and gas coexist

Question 20

What is the critical point?

Answer 20

End of vaporization curve, liquid-gas distinction disappears

Question 21

How does pressure affect water’s melting point?

Answer 21

Increases pressure lowers melting point below 0 degrees C

Question 22

What is the mass of a single molecule?

Answer 22

m = M / N_A

Question 23

What is the relation between p and T if V is constant?

Answer 23

p ∝ T (p V = n R T)

Question 24

How does pressure behave in small gas volumes (up to 100 m)?

Answer 24

Change is very small, so pressure is taken as constant everywhere

Question 25

How does pressure change with height in the atmosphere?

Answer 25

Pressure decreases as elevation (height above sea level) increases

Question 26

How does pressure change with height in a liquid?

Answer 26

Pressure changes with height; p2 + ρ g y2 = p1 + ρ g y1

Question 27

What is the equation for gas pressure as a function of height?

Answer 27

p = p0 e^(-g M y / R T), where p0 is pressure at height 0

Question 28

What is a formula for k(boltzman constant) in pV = NkT

Answer 28

k = R/Na

Question 29

convert g/mol to kg/mol

Answer 29

x 10^-3

Question 30

in what unit is molar mass

Answer 30

kg/mol

Question 31

on a maxbell boltzmann speed distribution curve what does Vmp and Vrms stand for and what is the area under the whole graph.

Answer 31

Vmp - most probable speed Vrms - average speed of particles Area = 1

Question 32

mean free time

Answer 32

(formula will be provided) average time between collisions

Question 32

mean free path

Answer 32

(formula will be provided) average distance between collisions

Question 33

when working with moles will you use k or R

Answer 33

R

Question 34

How is molar heat capacity related to the ideal gas constant?

Answer 34

C_p − C_v = R

Question 35

Internal energy

Answer 35

energy stored in a substance as kinetic and potential energy of its molecules. also determines the phase.

Question 36

U_0 mean in a potential energy curve

Answer 36

amount of energy needed for the atom to escape the attraction of its partner

Question 37

r_0 mean in a potential energy curve

Answer 37

equilibrium spacing - the attractive and repulsive forces cancel(net force = zero). the two atoms have minimum potential energy

Question 38

what is a critical point

Answer 38

changes smoothly above this point rather than undergoing a phase change

Question 39

fusion

Answer 39

solid + liquid

Question 40

vapor

Answer 40

vapor + liquid

Question 41

sublimation

Answer 41

solid+ vapor