Intro to Gas Laws

Question 1

gases exert ________ by ____________.

Answer 1

pressure; collisions

Question 2

gases are mainly ________ space.

Answer 2

empty

Question 3

what are the four main gas variables?

Answer 3

pressure (P), volume (V), temperature (T), number of moles (n)

Question 4

what is pressure?

Answer 4

the force exerted per unit of surface area (force/area)

Question 5

what is the SI unit for pressure

Answer 5

pascal (Pa)

Question 6

what units are expressed in pressure?

Answer 6

inches of mercury (in Hg)
centimeters of mercury (cm Hg)
millimeters of mercury (mm Hg)/torr

Question 7

what does psi stand for?

Answer 7

pounds per square inch

Question 8

what is the reference pressure? what is it? what can it be expressed in?

Answer 8

standard pressure. the normal pressure of the atmosphere at sea level on a fair weather day. p, v, t, n, atm.

Question 9

what are gases composed of?

Answer 9

tiny particles called molecules

Question 10

what are the standard pressure values?

Answer 10

1.00 atmosphere (atm)
760 torr
14.7 psi

Question 11

what is temperature?

Answer 11

a measure of the average kinetic energy and is measured in units called degrees

Question 12

where does the Kelvin scale start?

Answer 12

at absolute zero, the coldest temperature possible, where there is no motion of the gas molecules

Question 13

memorize this:

Answer 13

there are no negative values in Kelvin, it cannot be colder than 0 K

Question 14

K = ?
degreeC = ?

Answer 14

K = degreeC + 273
degreeC = K - 273

Question 15

what is the reference temperature? what is it?

Answer 15

standard temperature. the value is the normal freezing point of water at standard pressure

Question 16

what are the standard temperature values ?

Answer 16

0 degreeC, 273 K, 32degreesF

Question 17

what is STP?

Answer 17

standard temperature and standard pressure

Question 18

what values can be used for STP

Answer 18

0degreeC
273 K
1.00 atm
760 torr
14.7 psi

Question 19

what is Boyle’s Law? what is the equation at constant temperature ?

Answer 19

when the pressure gets bigger the volume gets smaller and vice versa as long as you keep the same temperature and the same number of molecules

V1 = P2
— — or P1V1 = P2V2
V2 P1

Question 20

what is Charles law? what is the equation ?

Answer 20

the relationship of temperature and volume for a sample of gas at constant pressure. when the temperature increases, so does the volume and vise versa as long as you keep the temperature the same.

V1 = V2
— —-
T1 T2

Question 21

memorize this:

Answer 21

when we work with gas law problems that involve a temperature change we must work with the Kelvin temperature scale

Question 22

if you double the Kelvin temperature, what happens to the volume? triple?

Answer 22

volume doubles; volume triples