Test 2- Phase change and Matter Flashcards Preview

Chemistry 1 > Test 2- Phase change and Matter > Flashcards

Flashcards in Test 2- Phase change and Matter Deck (100):
1

Solid

Doesn’t take shape of the container, definite volume, vibrational energy, lowest kinetic energy, no change in volume due to pressure.

2

Liquid

Takes shape of container, definite volume, vibrational and rotational energy, no change in volume due to pressure.

3

Gas

Takes shape of container, no definite volume, vibrational and rotational and translational energy, highest kinetic energy, pressure can be applied and volume will change.

4

Plasma

Just like gas except its composed of ions and electrons.

5

Both Liquids and gases are considered

Fluids

6

Phases at atomic level

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7

Endothermic

Energy going in/being absorbed

8

Exothermic

Energy coming out/being released

9

Endothermic examples

Sweating (energy going into sweat from your body in order to evaporate), Panting dogs (same as sweating since panting is the equivalent of sweating for dogs), chills when its 100 degrees and you get out of the pool (energy is being absorbed by the water from your body to evaporate)

10

Exothermic Examples

Making ice cubes (energy is being released in order to solidify)

11

Phase changes

•S > L - Melting - endothermic •L > S - Freezing - Exothermic •L > G - Evaporating or boiling - Endothermic •G > L - Condensing - Exothermic •S > G - Sublimation - Endothermic

12

Phase change diagram

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13

Heat of Fusion

The energy needed in joules to change one gram of substance from S>L or L>S

14

Chemical energy is called

Entropy

15

Energy is measured in

Joules

16

Cp

specific heat: Amount of energy needed in joules to raise on gram of substance by one Kelvin J/g degree Celsius or J/g degree Kelvin

17

Graph down vs. Graph up

•Down graph: energy released •Up Graph: Energy put in

18

KE vs. PE

•KE increases as temperature increases (lines going up/down) •PE energy increases during phase change (straight line)

19

Why is steam burn worse than hot water burn?

Hot water only transfers the energy it needs to evaporate while steam first needs to condense, then evaporate.

20

S>L vs. L>G

•S>L 334 J/g needs to overcome interatomic molecules •L>G 2260 J/g needs to overcome intermolecular and air pressure •More energy needed to go from L>G because of bonds and the air pressure acts as “bouncers” pushing the escaped liquid molecules back

21

Second law of thermodynamics

Describes direction of heat flow. Heat flows from a hotter object to a cooler one. Entropy of a system and its surroundings increase. Entropy is the fact that everything is moving towards disorganization.

22

Temperature _____ as water freezes

remains the same

23

Freezing point is the same as

melting point

24

Boiling point is the same as

condensing point

25

Water can exist as a ____ at zero degrees Celsius

liquid or a solid

26

Kinetic energy ______ during phase change

Remains the same

27

It will take ______ to cook an egg at lower pressure

more time

28

Temperature of boiling water in Death valley is _____

higher

29

KE=

KE= Average temperature. Doesn’t increase during phase change because temperature remains the same.

30

Pipes burst in the winter because __________

water expands as it freezes

31

Spaghetti takes longer to cook in the mountains because

the boiling temperature in higher altitudes is lower than at sea level so the pasta takes longer to cook. This is because there is less air pressure acting as bouncers, pushing the water back (air pressure).

32

Water freezes and ice melts at 0°C since

freezing point and melting point are the same

33

Water boils at

100dC

34

Ice is warmed to the melting point-

The frozen/solid molecules vibrate increasingly until they break apart. 0°C

35

Water is warmed to the boiling point-

Liquid molecules move faster and faster until they break apart. 100°C

36

Water is cooled to the freezing point-

Liquid molecules move slower and slower until they begin to stick together. 0°C

37

Lower air pressure, increased altitude will

not affect freezing point and melting point and decrease boiling point.

38

In a pressure cooker, the increased air pressure will

create a higher boiling point, making the food cook faster.

39

Drinking bird

The water is absorbed by the bird’s head, making it heavier which causes it to tip over because of gravity. The water evaporates off the head, cooling the temperature and causing the fluid to condense and the pressure to decrease. The water is forced to the tip of the bird. The vapor goes pack up and the bird becomes upright. Vapor travels from them bottom to the top until the pressure in both spheres equalize and the bird begins the process over again.

40

Miracle thaw does not possess amazing properties.

It is simply a slab of black aluminum with grooves. Aluminum is a good conductor, but not a superconductor. Also, their marketing principle that heat is transferred to the frozen food is simply a restatement of the second law of thermodynamics.

41

The size affects the heat flow because

it is fairly big and the bigger it is, the more heat is can absorb as evident by the equation Q=mΔTCp

42

Grooves act as a

water channel for the cold water, which would slow down the melting process.

43

Calometer lab- energy flow

The kinetic energy from striking the match it turned into chemical energy in the match and light and thermal energy. Then the energy transferred into the food and turned from chemical to thermal/light energy as it burned. It transferred into the water as thermal energy, which increased the movement of the molecules (temp) and kinetic energy.

44

Not all energy released

was accounted for

45

The law of the conservation of energy relates to this activity because

the law of conservation states that energy cannot be created or destroyed, but it can change form. In this activity, energy is not being created to heat the water; the energy is changing from its chemical form in the food to thermal energy, heating the water.

46

Nutritional Calorie vs. Calorie

A Nutritional Calorie is the amount of energy needed to raise the temperature of one kilogram of water by one degree Celsius. It is also the type of calorie you find in your food. A calorie is the amount of energy needed to raise one gram of water by one degree Celsius. One food Calorie=1000 calories.

47

Q=mHf or Q=mHv is used to

calculate energy during phase change (straight line)

48

Q= mΔTCp is used to

calculate the energy needed to raise/lower the temperature of a substance.

49

mΔTCp=mΔTCp

to calculate final temp or other variables

50

Specific heat of water:

4.184 J/g°C

51

If something has a smaller mass,

it won’t get as hot. So, if you put a piece of pizza on aluminum foil and put it in the oven to heat it, it wont get too hot since the mass of the foil is really small.

52

Classifying Matter chart

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Pure

•Uniform throughout •Can NOT be separated easily by ordinary physical means like separating m&m or Italian dressing, straining, filtering, or distilling •Distillation uses differences in boiling points (ex. Fractional)

54

Element

•Atoms are the smallest piece of an element •Cant be separated by physical or chemical means easily at all

55

Compound

•Elements turn into compounds through chemical change •Different from the elements that make up them •Unique/different properties both physical and chemical properties

56

Molecular

•2 or more non metals •Share electrons •Molecules-smallest piece •Not attached •Ex. Water

57

Ionic

•Metals and nonmetals •Transfer electrons •Big cluster- all attached •Crystal lattice structure/Ionic lattice (cluster of Na+Cl and –Cl) •Written in the simplest ratio formula unit (fu) •Chromatography?

58

Mixture

•Two or more substances •Each retains its chemical properties

59

Homogeneous

•Solution •Very small particles that are equally/evenly distributed •Ex. Coolaid •2 parts to a solution- Solvent and solute •Solvent- bigger part that does the dissolving •Solute- smaller part that gets dissolved •Soda is a solution when flat •Doesn’t have to be a solid and liquid- can be any phase. Ex. Alloy- 2 metals- pewter, brass, and bronze

60

Heterogeneous

Particles are not small enough to the point where they are invisible/solution is clear

61

Colloid or Colloid Dispersions

•Some medium sizes particles- light bounces or is bent when it hits the particles- the creates color •Ex. Mayonnaise- oil, vinegar, and egg clear, mixture becomes white. •Dispersed phase- smaller part •Despersed medium- Larger part

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L + L Colloid

Emulsion- mayo

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S + L Colloid

Sol- Blood

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S + G Colloid

Aerosol- Smoke

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L + S Colloid

Gel- Jelly

66

L + G Colloid

Liquid aerosol- Cloud, fog

67

G + L Colloid

Foam- shaving cream

68

Suspension

•Even larger particles that can be seen with the naked eye •Many times, particles are so large, they settle with gravity •Ex. Italian dressing, OJ with pulp, sand in water •Easy to separate

69

Characteristics of a mixture:

2+ elements are combines with one another and elements in a mixture are combined with out creating a mixture. A CHEMICAL CHANGE DOES NOT OCCURE WITHIN A MIXTURE

70

The 3 main types of mixtures are:

solution, colloid, and suspension

71

In a solution, particels are

too small to see

72

You unmix things chemically by

breaking some bonds

73

Mixtures that you can break down physically include

mud, trail mix, and salad

74

Many larger complex molecules are

just smaller molecules bonded together like building blocks

75

The starch molecule is

Amylose

76

Humans cant use the large molecules in proteins but can use

the amino acids that make up the proteins

77

Atoms are the

building blocks of building blocks

78

the atoms that repeatedly show up in macaroni salad.

CHONPS

79

How are all things related?

All things are made up of molecules and molecules are made of the same atoms, just arranged in different ways.

80

Examples of Solution, colloid, and Suspension-

Vinegar, mayonnaise, and mustard

81

The difference between an element and an atom is that

an atom is the smallest piece of an element and elements are made of atoms.

82

The difference between a compound and a molecule is that

a molecule is the smallest piece of a molecular compound while a compound is a pure structure composed of two or more separated elements.

83

The difference between an element and a compound is that

an element is made of one type of atom but a compound is made of two or more types of atoms

84

The difference between an atom and a molecule is that

an atom is the smallest piece of an element and a molecule is the smallest piece of a molecular compound.

85

The difference between a mixture and a pure substance is that

a mixture can be easily separated by ordinary means such as straining, filtering, distilling and pure substances cant.

86

The purpose of the water is to

act as a solvent to break apart the mixture of the ink and carry the ink up the paper.

87

Permanent markers would not work because

they are not soluble in liquid

88

Color separates and appears at different positions because

they travel at different rates because they are not all equally soluble and less soluble components will move at slower rates and more soluble components will move at faster rates.

89

Absorbent:

A substance that the mixture binds to.

90

Eluent:

A solvent specific to chromatography that does the dissolving.

91

Solvent:

In a solution, the substance in which the solute dissolves

92

Chromatography:

Analytical method used in lab to separate a mixture based on the components moving at different rates.

93

Retention factor:

A calculation that compares the distance traveled by an ion in solution to the distance traveled by the solvent.

94

Chemical change

changes the chemical state of something and cannot be easily separated. Drastic color change is an indication. Ex. Burning

95

Physical change

changes can be easily separated and does not change the chemical state of something. Ex. Dissolving, cutting hair, density

96

Laser disk clips

•Oxygen in a balloon will not explode. Oxygen doesn’t burn, only helps things burn •Thermite reaction makes molten iron •Hydrogen explodes and oxygen helps things explode •Hydrogen is twice as buoyant as helium but is reactive •Hydrogen and oxygen make the biggest explosion

97

• 7 diatonic elements:

Br, I, N, Cl, H, O, F- needs to bond

98

Break bond vs. bonds formed

•Bonds broken- energy absorbed- endothermic process •Bonds formed- energy released- exothermic process

99

Calorie vs. calorie vs. joule 

1 Calorie=1000 calories

1 joule= 1 calorie 

100

Energy vs. Work vs. joule 

Energy: the ability to do work

Work: exerting energy 

Joule: what energy is measured in