Ch 11 Section 2 Flashcards Preview

Chem > Ch 11 Section 2 > Flashcards

Flashcards in Ch 11 Section 2 Deck (58):
1

Robert Boyle discovered that gas pressure and volume are

related mathematically

2

the observations of Boyle and others led to the development of the

gas laws

3

the gas laws are simple mathematical relationships between the

volume, temperature, pressure, and amount of a gas

4

Robert Boyle discovered that doubling the pressure on a sample of gas at constant temperature reduces its

volume by one-half

5

reducing the pressure on a gas by one-half allows the volume of the gas to

double

6

the pressure of a gas is caused by moving molecules hitting the

container walls

7

if volume of container is decreased but same number of gas molecules is present at the same temperature then there will be more molecules per

unit volume

8

the number of collisions with a given unit of wall area per unit time will .... and therefore...

increase as a result; pressure will also increase

9

plotting values of volume versus pressure for a gas at constant temperature gives a

curve

10

the general-volume pressure relationship illustrated is called

boyle's law

11

boyle's law states that the volume of a fixed mass of gas varies inversely with the pressure at

constant temperature

12

Boyle's la can be expressed as : PV=

k

13

P is

pressure

14

V is

volume

15

k is a

constant

16

Since P and V vary inversely, their product remains the

same

17

because two quantities that are equal to the same thing are equal to each other, the relationship between changes of pressure and volume can be expressed as: P1V1 =

P2V2

18

P1 and V1 are

initial conditions

19

P2 and P2 are a

different set of conditions

20

given three of the four values P1, V1, P2, and V2, you can use this equation to calculate the fourth value for a

system at constant temperature

21

if pressure is constant, gases expand when

heated

22

when temperature increases, the volume of a fixed number of gas molecules must increase if the pressure is to

stay constant

23

at the higher temperature, the gas molecules move

faster

24

they collide with the walls of the container more frequently and with more

force

25

the volume of a flexible container must then increase in order for the pressure to

remain the same

26

the quantitative relationship between volume and temperature was discovered by the French scientist

Jacques charles in 1787

27

Charles's experiments showed that all gases expand to the same extent when heated through the

same temperature interval

28

charles found that the volume changes by 1/273 of the original volume for each

celsius degree, at constant pressure and initial temp of 0 degrees celsius

29

the same regularity of volume change occurs if a gas is cooled at

constant pressure

30

the kelvin temperature scale is a scale that starts at a temperature corresponding to

-273.15 degrees celsius

31

-273.15 degrees celsius is the lowest one

possible

32

the temperature -273.15 degrees celsius is referred to as absolute zero and is given a value of

zero in the Kelvin scale

33

K =

273.15 + degrees C

34

gas volume and kelvin temperature are

directly proportional to each other at constant pressure

35

charles's law states that the volume of a fixed mass of gas at constant pressure varies directly with the

Kelvin temperature

36

charles's law:
V =
k=

V = kT

V/T= k

37

the value of T is the

kelvin temperature

38

The ratio V/T for any set of volume-temperature values always equals the same

k

39

the form of charles's law that can be applied directly to most volume temperature problems involving gases is:

V1/ T1 = V2/ T2

40

V1 and T1 represent

initial conditions

41

V2 and T2 represent a

different set of conditions

42

when 3 of the 4 values T1, V1, T2, and V2 are known, the equation can be used to calculate the fourth value for a

system at constant pressure

43

the energy and frequency of collisions depend on the average

kinetic energy of molecules

44

for a fixed quantity of gas at constant volume, the pressure should be directly proportional to the

Kelvin temperature, which depends directly on average kinetic energy

45

for every kelvin of temperature change, the pressure of a confined gas changes by

1/273 of the pressure at 0 degrees C

46

Gay-Lussac's law: the pressure of a fixed mass of gas at constant volume varies

directly with the Kelvin temperature

47

Gay-Lussac's law is expressed as :
P =
k=

P = kT

P/T= k

48

in gay lussac's law k is constant that depends on the

quantity of gas and volume

49

for given mass of gas at constant volume, the ratio P/T is the same for any set of

pressure-temperature values

50

unknown values can be found using the following form of gay-lussac's law:

P1/ T1 = P2/ T2

51

a gas sample often undergoes changes in temperature, pressure, and volume all at the

same time

52

the combined law expresses the relationship between

pressure, volume, and temperature of a fixed amount of gas

53

combined gas law: k=

PV/ T

54

in combined gas law, k depends on the

amount of gas

55

combined gas law can also be written as:

P1V1/ T1 = P2V2/ T2

56

each of the gas laws can be obtained from the combined gas law when the

proper variable is constant

57

boyle's law is obtained from the combined gas law when

temperature is constant

58

because T1 = T2, T1 and T2 will canel out on both sides of the combined gas law equation, giving

Boyle's law