Matter & Energy – Gases Aim: How do gases react due to changes in temperature, pressure, and volume?. Do Now: According to Reference Table H, which substance has the highest vapor pressure at 75 o C? HW:. Pressure & Moles. Rigid container pump in more air What happens to # of collisions?
According to Reference Table H, which substance has the highest vapor pressure at 75oC?
What happens to KE of mlcls as the T increases?
What happens to size of container (if the walls are flexible?)
The (1) refers to initial conditions, the (2) refers to new/final conditions
At a temperature of 273 K 400ml gas sample has a pressure of 101.3kPa. If the pressure is changed to 50.65kPa, at which temperature will this gas sample have a volume of 551ml?
P1V1 = P2V2
P1 = 101.3kPa 101.3kPa x 400ml = 50.65kPa x 551ml
V1 = 400ml 273K T2
T1 = 273K 101.3kPa x 400ml x T2 = 50.65kPa x 551ml x 273K
P2 = 50.65kPa T2 = 188K
V2 = 551ml
T2 = X
P1V1 = P2V2
P is constant, so we cross it out!
V1 = V2
Initial Conditions Final Conditions
P1 = 1 atm P2 = 2 atm
V1 = 20 L V2 = ?
T1 = 273 K T2 = 200 K
(Note: the T & P
values are from Table A!
We use the atm unit for
pressure b/c atm is used in
the problem, not kPa.)
A sample of gas confined to a volume of 10 L at 10 to 2 atm and the temperature decreases to 200 K, what is theoC and 2 atm is subjected to a pressure increase to 2.5 atm and a temperature decrease of 10oC. What is the new volume?
remains the same
directly proportional to the Celsius temperature.
inversely proportional to the Kelvin temperature.
inversely proportional to the Celsius temperature