15.1 - 15.4

Question 1

assumptions of an ideal gas

Answer 1

a large number of molecules

the volume of molecules is negligible compared to the gas

molecules have perfectly elastic collisions

time of collisions is negligible compared to the time between collisions

the electrostatic force between molecules is negligible

Question 2

why do gases exert pressure

Answer 2

random collisions with the wall cause a force to be exerted (Newtons second/third law). if the total force is F then the pressure = F/A where A is the area of the wall

Question 3

relationship between pressure and volume

Answer 3

pressure is inversely proportional to volume if mass and temperature are constant. P ∝ 1/V

Question 4

relationship between pressure and temperature

Answer 4

pressure is directly proportional to the absolute temperature (kelvin) if mass and volume are constant. P∝T

Question 5

how is the root mean square speed found

Answer 5

the velocity of each atom is squared
the average of these squared velocities is found
the average is square rooted

Question 6

why is the root mean square speed used

Answer 6

because the average velocity in an ideal gas would be zero since it’s a vector.

Question 7

what is the Boltzmann constant

Answer 7

the molar gas constant (8.31) divided by Avogadro’s constant (6.02*10^23). it relates the average kinetic energy to the temperature of an ideal gas