Chemistry

Question 1

Which of the following correctly reflects the relationship between the volume and the external pressure on a gas at constant temperature?

Answer 1

1. As pressure decreases, volume will increase.

2. Pressure and volume are inversely prepositional.

Question 2

How does a gas exert pressure?

Answer 2

The moving gas particles strike each other and the wall of the container, exerting a force.

Question 3

Pressure =

Answer 3

Force/Area

Question 4

The SI unit for pressure is?

Answer 4

The Pascal (pa)

Question 5

Boyles Law?

Answer 5

states the at constant temperature, the volume occupied by a fixed amount of gas is inversely promotional to the applied pressure. This means that as the pressure on the gas increases, the volume will decrease.

Question 6

Pressure decreases with ?

Answer 6

Altitude

Question 7

Manometers

Answer 7

Used to measure the pressure of a gas in an experiment

Question 8

Barometer

Answer 8

Uses Mercury to measure atmospheric pressure = 760mmHg.

Invented by Torricelli

Question 9

Closed-end Manometer

Answer 9

a mercury-filled, curved tube is closed at one end and attached to a flask at the other. When the flask is evacuated, the mercury levels in the two arms of the tube are the same because no gas exerts pressure on either mercury surface. When a gas is in the flask, it pushes down the mercury level in the near arm, causing the level to rise in the far arm. The difference in column heights (Δh) equals the gas pressure.

Question 10

Open-end Manometer

Answer 10

also consists of a curved tube filled with mercury, but one end of the tube is open to the atmosphere and the other is connected to the gas sample. The atmosphere pushes on one mercury surface, and the gas pushes on the other. Again, Δh equals the difference between two pressures. But, when using this type of manometer, we must measure the atmospheric pressure with a barometer and either add or subtract Δh from that value.

Question 11

1 atm=

Answer 11

760 mmHg

Question 12

1 torr=

Answer 12

1 mmHg

Question 13

1 atm=

Answer 13

101.325 kPa

Question 14

Charles’s Law

Answer 14

at constant pressure, the volume occupied by a fixed amount of gas is directly proportional to its absolute (Kelvin) temperature

Question 15

Volume of 1 mole of an ideal gas at STP?

Answer 15

22.4L

Question 16

0 Kelvin is equal to what C

Answer 16

-273.15 C

Question 17

Avagadro’s Law

Answer 17

at fixed temperature and pressure, equal volumes of any ideal gas contain equal numbers (or moles) of particles.

Question 18

STP

Answer 18

0C (273.15K) 1 atm (760 torr)

Question 19

R the universal gas constant is equal to

Answer 19

0.0821 atm . L/ mol . K

Question 20

Thermodynamics

Answer 20

the study of energy and its transformation

Question 21

Thermochemistry

Answer 21

is a branch of thermodynamics that deals with the heat involved in chemical and physical changes.

Question 22

1st Law of Thermodynamics

Answer 22

states that the total
energy of the universe is constant.
Esystem=-Euniverse

Question 23

Units of Energy

Answer 23

J

Question 24

Density of a gas

Answer 24

mass/volume

(O2: 32g/22.4L=1.43g/L

Question 25

What is moles = to

Answer 25

mass/Molar mass Pv=(m/M)RT d=P(M)/RT

Question 26

The density of a gas is ____ _____ to the temperature

Answer 26

Inversely Proportional

Question 27

The density of a gas is ____ _____ to the pressure

Answer 27

directly proportional

Question 28

An alternative approach for finding the density of most simple gases, but at STP only, is to divide the molar mass by the standard molar volume, 22.4 L:

Answer 28

d=m/v

Question 29

Through another rearrangement of the ideal gas law, we can determine the molar mass of an unknown gas or a volatile liquid (one that is easily vaporized):

Answer 29

M=mRT/PV

Question 30

in a mixture of unreacting gases, the total pressure is the sum of the partial pressures of the individual gases:

Answer 30

Daltons Law of partial pressure

Question 31

Mole Fractions

Answer 31

Mole of N2/Total amount mole | nN2/nN2 + nH2 (mole fractions for N2 and H2

Question 32

If the total pressure is due to the total number of moles, the partial pressure of gas A is the total pressure multiplied by the _____?

Answer 32

Mole fraction

Question 33

Kinetic Molecular Theory | Postulate 1

Answer 33

Particle volume. A gas consists of a large collection of individual particles with empty space between them. The volume of each particle is so small compared with the volume of the whole sample that it is assumed to be zero; each particle is essentially a point of mass.

Question 34

Kinetic Molecular Theory | Postulate 2

Answer 34

Particle motion. The particles are in constant, random, straight-line motion, except when they collide with the container walls or with each other.

Question 35

Kinetic Molecular Theory | Postulate 3

Answer 35

Particle collisions. The collisions are elastic, which means that, like minute billiard balls on a frictionless billiards table, the colliding molecules exchange energy but do not lose any energy through friction. Thus, their total kinetic energy (Ek) is constant. Between collisions, the molecules do not influence each other by attractive or repulsive forces.

Question 36

Distribution of molecular speeds at 3 temperatures

Answer 36

- the curves flatten and spread at higher temperatures | - the most probable speed (the peak of each curve) increases as the temperature increases.

Question 37

Mean free path of a gas particle

Answer 37

The average distance a gas particle travels between collisions (either with other particles or the wall)

Question 38

Diffusion

Answer 38

the movement of one gas through another

Question 39

Effusion

Answer 39

process of a gas escaping through a tiny hole

Question 40

Change in internal E

Answer 40

``` ∆E= E Final-E initial ∆E= E products - E reactants ```

Question 41

By releasing some energy in a transfer to the surroundings

Answer 41

E final < E initial

Question 42

By absorbing some energy in a transfer from the surroundings

Answer 42

E initial < E final

Question 43

∆E = q + w

Answer 43

The total change in a system’s internal energy is the sum of the energy transferred as heat and/or as work:

Question 44

Positive Energy

Answer 44

Energy transferred into the system is positive because the system ends up with more energy.

Question 45

Negative Energy

Answer 45

Energy transferred out from the system is negative, because the system ends up with less energy.

Question 46

For a system that transfers energy only as heat (q) and does no work (w = 0), we have

Answer 46

∆E = q

Question 47

For a system that transfers energy only as work, q = 0

Answer 47

∆E = w

Question 48

A _____ function is path independent, meaning that only the ____ and ____ conditions are needed to measure the net change that occurred.

Answer 48

state initial Final

Question 49

A change in ∆H (enthalpy) is equal to the change in heat (q) when the system is at constant ______.

Answer 49

Pressure

Question 50

All common Sulfates soluble except

Answer 50

CaSO4, SrSO4, BaSO4, AgSO4, PbSO4

Question 51

All common fluorides soluble except

Answer 51

PbF2, Flourides of group 2A

Question 52

All common Chlorides, bromides, and Iodides soluble excpet

Answer 52

Ag+, Pb2+, Cu+, Hg22+

Question 53

All common Nitrates, acetates, and percholrates soluble

Answer 53

no exceptions | NO3-, CH3C00-, CLO4-

Question 54

All common compounds of Group 1A soluble

Answer 54

no exceptions

Question 55

All common metal hydroxides are insoluble except

Answer 55

Group 1A hydroxides, Ca(OH)2, Sr(OH)2, and Ba(OH)2

Question 56

All common carbonates (CO2-3) and phosphates (PO34-) are insoluble except

Answer 56

carbonates and phosphates of Group 1A, and NH4+

Question 57

All common sulfides are insoluble except

Answer 57

Sulfides of Group 1A, and NH4+