Kinetic-Molecular Theory Flashcards

1
Q

Vapor

A

Gas produced from a liquid or solid under normal conditions (vapor pressure must be equal to that of the atmosphere)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Ideal gas

A

Imaginary gas that perfectly fits all of the assumptions of the kinetic-molecular theory. A gas that behaves independently of its environment (mostly noble gases and diatomic molecules)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Assumptions

A

A. Gases consist of a large number of tiny particles with much space in between
B. Collisions occur as elastic collisions, no net loss of kinetic energy
C. Gases are in constant, rapid, random motion
D. No attractive or repulsive forces between gases
E. Average kinetic energy is constant and depends on temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Johann van Helmont (1662)

A

Used “gas” to describe the most energetic phase of matter (derived from the Greek “chaos”, original matter on Earth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Expansion

A

Allows gas to take the shape of the container

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pressure

A

Force per unit area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Barometer

A

Instrument to measure atmospheric pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Manometer

A

Instrument to measure pressure produced in a lab reaction or tank

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Density

A

Measure of mass per volume (for gases g/l)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Diffusion of gases

A

Random spreading of gas in uniform dimensions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Effusion

A

Controlled escape of gas through a hole or pore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Condensation temperature

A

The point where gas molecules form a liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Real gases

A

Don’t behave completely according to the kinetic-molecular theory; intermolecular forces provide interactions that may change gas properties or behaviors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Van der Waal forces

A

General terms for weak intermolecular attractions between molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

London dispersion forces

A

Caused by motion of electrons, increases as # of electrons increases. Can occur in any molecule to induce temporary polar behavior.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Dipole-dipole interactions

A

Electrostatic attractions based on distinct polarity of molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Hydrogen bonding

A

Hydrogen bonded to a highly electronegative atom is attracted to an unshared pair of electrons in a nearby molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Definite volume

A

Won’t expand, will take the shape of the container (liquid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Incompressible (liquid)

A

Liquids equalize pressure, particles are close together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Fluidity

A

Ability to flow and be poured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Diffusion of liquid

A

Particles have motion and randomly spread, but more slowly than gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Cohesion

A

Force of attraction between molecules of the same substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Adhesion

A

Force of attraction between different substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Surface tension

A

Force that pulls adjacent parts of a liquid’s surface together resulting in the smallest surface area possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Capillary action

A

Attraction of the surface of a liquid to the surface of a solid; tends to move a liquid against gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Definite shape

A

Exists in a fixed form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Definite volume

A

All surfaces are free and defined

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Incompressible (solid)

A

Structure can’t be altered without a phase change

29
Q

Amorphous

A

Without form, that which appears to have inconsistent or random particle arrangement

30
Q

Crystal

A

Homogeneous substance bounded by plane surfaces making definite angles, giving a geometric form

31
Q

Crystal lattice

A

Pattern of pints in a crystal

32
Q

Crystallography

A

Science of classifying crystal shape with X-ray diffraction

33
Q

Unit cell

A

Smallest portion of a crystal lattice that shows the pattern of the lattice

34
Q

Ionic crystal

A

Atoms held together by electrostatic forces, hard, high melting point (ex: NaCl)

35
Q

Covalent crystal

A

Covalent bonds, like one big molecule, very high melting point (ex: diamond)

36
Q

Metallic crystal

A

Atoms of metal sit on lattice points and outer electrons float around the lattice, very dense, high melting point (ex: copper)

37
Q

Molecular crystal

A

Contain recognizable molecules in their structure, held together by van der Waal forces and hydrogen bonding, soft, low melting point (ex: rock candy/sucrose)

38
Q

Isometric (cubic)

A

3 axes at right angles are equal lengths

Iso = same

39
Q

Hexagonal

A

3 equal axes intersect at 60 degree angles, a vertical axis of a different length is at a right angle to these axes (note: four axes)

40
Q

Tetragonal

A

3 axes at right angles, only two are at equal lengths

41
Q

Trigonal

A

3 equal axes at non right angles

42
Q

Orthorhombic

A

3 unequal axes at right angles

43
Q

Monoclinic

A

3 unequal axes, one non right angle

44
Q

Triclinic

A

3 unequal axes, three non right angles

45
Q

Supercooled liquids

A

Substances that retain certain liquid properties even at temperatures at which they appear to be solid

46
Q

Gas liquification

A

Michael Faraday 1823, English chemist; cooling and compressing gases at the same time would yield a liquid; a critical point for pressure and temperature. Faraday liquified Cl, CO2, HSO2, and HBr

47
Q

Volatile liquids

A

Liquids that easily evaporate due to weak intermolecular forces

48
Q

Molar heat of vaporization

A

Amount of heat energy needed to melt one mole of solid at its melting point

49
Q

Molar heat of fusion

A

Amount of heat energy needed to melt one mole of solid at its melting point

50
Q

Closed system

A

No substances are added or lost, but energy changes freely occur

51
Q

Physical equilibrium

A

State in which 2 opposing physical changes occur at equal rates in the same system

52
Q

Equilibrium vapor pressure

A

Pressure exerted by a vapor in equilibrium with its liquid

53
Q

Dynamic equilibrium

A

Forward and backward reaction reached a point where there is no further change in the quantities of substances, but the reactions are still taking place

54
Q

Henri Le Châtelier’s Principle 1884

A

A. If a system is subjected to stress, the equilibrium will change in order to relieve the stress
B. Equation will shift based on concentration, partial pressure of gas (molecule # is important), and temperature; consider if the reaction is endothermic (H is positive) or exothermic (H is negative)
C. Catalysts don’t change equilibrium, they only speed up the rate at which dynamic equilibrium is met

55
Q

Phase

A

Part of a system that has uniform properties and composition; phase changes are physical changes based on heat content

56
Q

Triple point

A

The temperature and pressure conditions at which the solid, liquid, and vapor of the substance can coexist at equilibrium

57
Q

Critical point

A

Indicates a critical temperature and pressure

58
Q

Critical temperature

A

Temperature above which the substance cannot exist as a liquid

59
Q

Critical pressure

A

Lowest pressure at which the substance can exist as a liquid at the critical temperature

60
Q

Supercritical fluid

A

A material that can be either liquid or gas, used above the critical point where gases and liquids can coexist. This fluid has gaseous properties of penetrating substances, and liquid properties of dissolving materials into their components

61
Q

Density of water

A

Liquid: 1 g/ml, less dense as ice (.92g/ml), hence it floats on water

62
Q

High specific heat index of water

A

Absorbs and releases a lot of energy when getting hot or cold; helps regulate air temperature

63
Q

Water pH

A

7

64
Q

Percentage of water in life

A

70-90% of all living matter

65
Q

Hydrate

A

Crystallized substance that contains a definite # of water molecules in the structure (if water lost, anhydrous)

66
Q

Hydrolysis

A

Chemical reaction in which water molecules are split and the parts are added to the products

67
Q

Effervescence

A

Rapid evolution of a gas when a dry substance reacts with water

68
Q

Efflorescence

A

The loss of some or all of the water of crystallization when exposed to a warm or dry environment

69
Q

Deliquescence

A

Absorbing water by a substance from the air, making it moist or resulting in a solution