Textbook Topic 9- Gas law

Question 1

Gas pressure is caused by… although the force is small…..

Answer 1

the force exerted by the gas molecules colliding with the surfaces of objects. Although the force of each collision is very small a large SA experience lots of collision in a short time causing high air pressure

Question 2

Atmospheric pressure is caused by

Answer 2

the weight of the column of air molecules in the atmosphere above an objet

Question 3

Pressure can be increased by (Not temp or volume) (2)

Answer 3

increasing force or decreasing the area

Question 4

In terms of weather, low-pressure systems occur when (2)

Answer 4

the earths atmospheric pressure is lower than the surrounding environment

moist air rises and condenses producing clouds

Question 5

as you go up the troposphere (3)

Answer 5

air density, air pressure and temp decrease

Question 6

hydrostatic pressure

Answer 6

pressure by a fluid due to gravity

Question 7

Ideal gas

Answer 7

a hypothetical construct that real gases approximate under certain conditions

Question 8

effects of temp on the volume of a given amount of a confined gas at constant pressure

Answer 8

the volume increases as the temp increases and decrease as the temp decreases

Question 9

This relationship between temperature and pressure is observed for any sample of gas confined to a constant volume

not go up and down

Answer 9

Temperature and pressure are linearly related and proportional is temp is in Kelvin

Question 10

Boyle’s Law

Answer 10

The volume of a given amount of gas held at constant temp is inversely porprotional to the pressure under which it is measured

Question 11

If volume increase by a certain factor, the pressure will_____ assuming ____ and _____ do not change

Answer 11

decrease by the same factor

moles and temp

Question 12

Tell me how breathing works with the lungs and shit

Answer 12

Breathing occurs because the expanding and contracting of your lungs causes air pressure difference causing air to be drawn into and forced out

Question 13

Avogadros law

Answer 13

For a confined gas the volume and number of moles are proportional if the pressure and temp remain the same

Question 14

ideal gas law (3)

Answer 14

combining all the laws with p,v,,n,t

Pv=nRT

describes gas under ideal conditions

Question 15

ideal conditions of gas us holds true to real life when conditions are:

Answer 15

gas is under low pressure and high temp

Question 16

combined gas law when moles are the same

Answer 16

P1V1/T1=P2V2/T2

Question 17

Combined gas law when moles are different

Answer 17

P1V1/n1T1=P2V2/n2T2

Question 18

If the number of moles of an ideal gas are kept constant under two different sets of conditions, a useful
mathematical relationship called the combined gas law. In the combined gas law, both sets of conditions are equal to the product of….

Answer 18

moles(R)

nR

Question 19

general units for combined gas law

Answer 19

atm, K, L

Question 20

standard temperature and pressure

Answer 20

1 mole of an ideal gas have v=22.4L

p=1atm

T=273.15K

Question 21

Difference between density and ideal gas law

Answer 21

Density is an characteristic determined by its identity

ideal gas law relates these properties in identical fashion regardless of the chemical identity of the gas

Question 22

density formula

Answer 22

d= (molar mass)(p)/(RT)

Question 23

Daltons’s Law of partial pressures+ equation

Answer 23

The total pressure of a mixture of ideal gases is equal to the sum of the partial pressures of the component gases

Ptotal= Pa+Pb+Pc….

Question 24

Each individual gas in a mixture exerts

Answer 24

the same pressure that it would exist if it were present alone in the container

Question 25

the coefficient infront of the chemical equation signifies

Answer 25

the moles which is also equal to the volume

Question 26

Kinetic molecular theory which one describes amonton law?

Answer 26

If the temperature is increased, the average speed and kinetic energy of the gas molecules increase. If the volume is held constant, the increased speed of the gas molecules results in more frequent and more forceful collisions with the walls of the container, therefore increasing the pressure

Question 27

Kinetic molecular theory which one describes Charles law?

Answer 27

If the temperature of a gas is increased, a constant pressure may be maintained only if the volume occupied by the gas increases. This will result in greater average distances traveled by the molecules to reach the container walls, as well as increased wall surface area. These conditions will decrease the both the frequency of molecule-wall collisions and the number of collisions per unit area, the combined effects of which balance the effect of increased collision forces due to the greater kinetic energy at the higher temperature.

Question 28

Kinetic molecular theory which one describes Boyles law?

Answer 28

If the gas volume volume of a given amount of gas at a given temperature is decreased (that is, if the gas is compressed), the molecules will be exposed to a decreased container wall area. Collisions with the container wall will therefore occur more frequently and the pressure exerted by the gas will increase

Question 29

The average speed of a gas depend

Answer 29

its molar mass—the lighter the mass, the faster the average speed.

Question 30

speed of particles in a gas sample not mass related one

Answer 30

individual molecules have varying speed but the molecular speed distribution (after an hour the curve is still the same) and average speed is constant (after 1 hour average speed is still the same).

Question 31

Maxwell-Boltzmann

Answer 31

depicts the relative numbers of molecules in a bulk sample of gas that possesses a given speed

Question 32

if temp of a gas increases,......+effect of the Maxwell-Boltzmann graph

Answer 32

its KE value also increase, more molecules have higher speeds and fewer molecules have lower speeds, and the distribution shifts toward higher speeds overall, that is, to the right.

Question 33

Gases composed of lighter molecules have more.....+speed distribution (2)

Answer 33

high-speed particles with a speed distribution that peaks at relatively higher speeds

Question 34

Gases consisting of heavier molecules have more....+speed distribution (2)

Answer 34

more low-speed particles a speed distribution that peaks at relatively lower speeds.

Question 35

compressibility factor (Z)+ how do you know ideal gas law not accurate (2)

Answer 35

molar volume of gas at same temp+pressure/molar volume of ideal gas at same temp+pressure any deviation from 1 is an indication of non-ideal behavior

Question 36

when does ideal gas law fail

Answer 36

at relatively high pressures

Question 37

how do real gas behaviour fail at Boyle's law?

Answer 37

Boyles law states that as pressure increase, volume decrease. gas forces in-between will decrease volume like suppose to but also decrease pressure which should have increased even more since u have this extra volume decrease However, when the gases are crowded tgt with high pressure and low volume, they start sticking to eachother this decreases the pressure (if the volume is constant) or decreasing the volume (at constant pressure) (Figure 9.36). This change is more pronounced at low temperatures because the molecules have lower KE relative to the attractive forces, and so they are less effective in overcoming these attractions after colliding with one another.