lesson 1

Question 1

what are phases of matter?

Answer 1

solid -> definite shape and volume.
liquid -> shape depends on container, definite volume.
gas -> takes on shape and volume of container.

Question 2

what causes phases to change?

Answer 2

phases change as energy increase.

Question 3

what is properties of gases?

Answer 3

no defined shape or volume
density in lower than other states.
can be compressed.
exerts pressure on surroundings.

Question 4

what is pressure? + units.

Answer 4

force exerted by gas on its surroundings.

atm, mmHg, torr, pascal.

Question 5

1 atm = ? mmHg

Answer 5

1 atm = 760 mmHg

Question 6

1 atm = ? torr

Answer 6

760 torr

Question 7

torr = ? pa

Answer 7

133.32 pa

Question 8

1 atm = ? pa

Answer 8

101325 pa

Question 9

what is Boyle’s gas law?

Answer 9

PV = k

there is an inverse relation between pressure and volume at constant temperature.

Question 10

when can we use Boyle’s gas law?

Answer 10

when it’s at constant temperature and in ideal gas or as close to ideal.

Question 11

what is Charles’s gas law?

Answer 11

V1 / T1 = V2 / T2

volume and temperature increase linearly at constant pressure.

Question 12

when can we use Charles’s law?

Answer 12

at constant pressure.

pressure in kalvin.

Question 13

what is Avogadro’s law?

Answer 13

V1 / n1 = V2 / n2

The total number of atoms is proportional to volume.

Question 14

when is Avogadro’s law used?

Answer 14

when it’s at a constant temperature and pressure.

Question 15

what is ideal gas law?

Answer 15

combines Avogadro + Boyle + Charles law.

PV = nRT

Question 16

R in gas law equals?

Answer 16

R = 0.08206 L.atm/k.mol

Question 17

density of gas.

Answer 17

d = molar mass * P / RT

Question 18

what is Dalton’s law of partial pressure.

Answer 18

P(total) = P1 + P2 + P3 + ……

Question 19

what is diffusion?

Answer 19

term used to describe the mixing of gases,

Question 20

what is effusion?

Answer 20

term used to describe the passage of a gas through a tiny orifice into an evacuated chamber.

Question 21

Graham’s law of effusion to describe the motion of gas in diffusion?

Answer 21

diffusion -> mixing of gas happens because of random motion and collision

Question 22

Graham’s law of effusion to describe the motion of gas in effusion

Answer 22

effusion -> the gas molecules escape without collision through a tiny hole into a vacuum.

Question 23

Graham’s law of effusion.

Answer 23

the relative rates of effusion of two gases at the same temperature and pressure are = the inverse ratio of the square roots of the masses of gas particles.

Question 24

molar volume at STP = ?

Answer 24

22.42 L

Question 25

what are the standard temperature and pressure?

Answer 25

temperature = 0 C
pressure = 1 atm