CHAPTER TWO: MATTER AND ENERGY Flashcards

1
Q

The EARLY GREEK PHILOSOPHERS (6th Century B.C.) proclaimed the existence of _______ and a ________.
M

A

Atoms and a Void.

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2
Q

What is ALCHEMY (1st-16th Century A.D.)?

What are some of the contributions of this tradition?

M

A

Alchemy is the early study of chemistry.

Contributions:

  • qualitative experimentation
  • important techniques
  • methods
  • glassware
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3
Q

What are the contributions of the MEDICAL-TECHNOLOGICAL tradition (13th-17th century A.D.)?

M

A
  • quantitative experimentation
  • balances
  • furnaces
  • crucibles
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4
Q

What are the three forms that MATTER takes? Describe each one….
M

A

SOLID: has a definite shape and volume. Strong attractive forces hold the particles such as atoms or molecules close together. The particles are arranged in such a rigid pattern they can only vibrate slowly in fixed positions.

LIQUID: has a definite volume, but not a definite shape. The particles move in random directions but are sufficiently attracted to each other to maintain a definite volume, although not a rigid structure (takes the shape of the container).

GAS: does not have a definite shape or volume. The particles are far apart, have little attraction to each other, and move at high speeds, taking the shape and volume of their container.

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5
Q

What is a PURE SUBSTANCE/CHEMICAL and
what are the TWO kinds of pure substances?

M

A

A pure substance/chemical is MATTER that has a fixed or definite composition.

The two kinds of pure substances are ELEMENTS and COMPOUNDS.

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6
Q

What is an ELEMENT?

Give 5 examples of an element

M

A

An element is the simplest type of a pure substance.

It is composed of only ONE type of material. Every element is composed of ATOMS that make up each type of matter. (Ex: silver is composed of silver atoms, iron of iron atoms, etc.)

ELEMENTS:

  • elemental iron: Fe (solid)
  • elemental bromine: Br2 (liquid)
  • elemental hydrogen: H2 (gas)
  • argon: Ar (gas)
  • oxygen: 02
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7
Q

What is a COMPOUND?

Give 3 examples of compounds.

M

A

A compound is also a pure substance, but it consists of atoms of two or more elements always chemically combined in the same proportion.

In compounds, the atoms are held together by attractions called BONDS, which form small groups of atoms called MOLECULES. (Ex: H20- water and H202- hydrogen peroxide…are different compounds, which means they have different properties)

COMPOUNDS:

  • H20 (l)
  • C12H22O1 (s)
  • NaCl
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8
Q

An important difference between COMPOUNDS and ELEMENTS is that compounds can be ____________, whereas elements ____________.

M

A

An important difference is that COMPOUNDS can be broken down by chemical processes (not physical methods) into simpler substances, whereas ELEMENTS cannot be broken down further by a chemical reaction.

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9
Q

What is a MIXTURE?

M

A

In a MIXTURE, two or more substances are physically mixed, but not chemically combined (ex: air, steel, tea).

In any mixture, the proportions of the components can vary.

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10
Q

Why can physical processes be used to separate MIXTURES?

M

A

because there are no chemical interactions between the components (ex: a mixture of different coins)

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11
Q

What are the two types of MIXTURES? Describe each and give examples of each….

M

A

HOMOGENEOUS: also called a SOLUTION; the composition is uniform throughout the sample. Ex: air, sea water. Examples:

  • NaCl
  • air (80%N2, 20% 02, <1% other gases)
  • alloys: bronze and brass

HETEROGENEOUS: the components do not have a uniform composition throughout the sample. Ex: oil and water, bubbles in a soda. Examples:

  • blood: is a suspension
  • milk: is a colloid
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12
Q

List two ways that mixtures are separated by various methods:

  • solids separated from liquids by….
  • different compounds of a liquid mixture by….

M

A

Solids are separated from liquids by FILTRATION, which involves pouring a mixture through a filter paper set in a funnel.

In CHROMATOGRAPHY, different components of a liquid
mixture separate as they move at different rates up the surface of a piece of chromatography paper.

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13
Q

Changes of State (when matter is converted from one state to another- what are each of these called and what happens?):

  1. solid to liquid = ________
  2. liquid to solid= _______

M

A
  1. MELTING -when heat is added to a solid, the particles move faster. At a temp called the MELTING POINT (mp), the particles of a solid gain sufficient energy to overcome the attractive forces that hold them together. The particles separate and move about in random patterns
  2. FREEZING- if the temperature is lowered, kinetic energy is lost, the particles slow down, and attractive forces pull the particles close together. The liquid changes to a solid at the FREEZING POINT (fp) which is the same temperature as its melting point. Every substance has its own freezing (melting point).
  3. vaporization
  4. condensation
  5. sublimation
  6. deposition
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14
Q

During a change of state, the temperature of a substance _______ ________.
M

A

Remains constant.

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15
Q

What are PHYSICAL PROPERTIES?

List 5 typical physical properties in chemistry.
M

A

PHYSICAL PROPERTIES are those characteristics that can be observed or measured without affecting the identity of a substance.

5 typical physical properties in chemistry:

  • appearance: color, shape
  • melting point
  • boiling point
  • conductivity: thermal or electrical
  • solubility
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16
Q

Water is a substance that is commonly found in all three states- solid, liquid and gas. When matter undergoes a PHYSICAL CHANGE, its state or appearance changes and its composition __________.
M

A

Remains the same (all three states are water).

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17
Q

In a PHYSICAL CHANGE OF STATE, are new substances produced?

M

A

NO

Ex: if you dissolve salt in water, the appearance of the salt changes, but you can re-form the salt crystals by heating the mixture and evaporating the water.

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18
Q

What are CHEMICAL PROPERTIES?

When a CHEMICAL CHANGE takes place, the original substance ____________________…
M

A

CHEMICAL PROPERTIES are those that describe the ability of a substance to change into a new substance.

When a CHEMICAL CHANGE takes place, the original substance is converted into one or more new substances, which have different physical and chemical properties.

Ex: chemical properties of Na react with H20 to give Na0H….or with 02 to give Na20

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19
Q

What is the NORMAL BODY TEMPERATURE range?

What is hyperthermic in degrees C and degrees F?

M

A

98.6 +or-2.0 degrees F

Hyperthermic:

  • > 41 degrees C
  • > 106 degrees F
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20
Q

One degree Celsius = ______ K

One degree Fahrenheit= _____ C + ______
M

A

degree C= 273 K

degree F= 9/5 degree C + 32

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21
Q

Define ENERGY

What is the formula for WORK?

What is the formula for FORCE?
M

A

Energy is the ability to do work (to accelerate a mass through a distance).

WORK= FORCE x DISTANCE

FORCE= MASS x ACCELERATION x DISTANCE

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22
Q

What is HEAT (also known as _______)……?

What does TEMPERATURE measure?
M

A

Heat (also known as thermal energy) is the energy associated with the motion of particles.

Temperature is a measure of average kinetic energy of the particles of a substance

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23
Q

What are two forms of energy? Define each one.

M

A

POTENTIAL ENERGY- stored energy due to:
* location (A boulder resting on top of a mountain has potential energy because of its location- if it rolls down the mountain, the potential energy becomes kinetic energy)

  • OR chemical composition (foods and fossil fuels have potential energy in their molecules- when you digest food or burn gasoline in your car, potential energy is converted to kinetic energy to do work)

KINETIC ENERGY- energy of motion; any object that is moving has kinetic energy.

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24
Q

What are 3 units of energy?

M

A

J (joule)- this is the SI unit of energy and work

cal (calorie)- this is from the Latin “calor”, meaning “heat”

nutritional calorie: Cal = 1000 cal= 1kcal

25
Q

1 cal = _______ J

1 kcal is equal to _______ calories

1 kJ is equal to _______ joules
M

A

1 cal = 4.184 J
This is EXACT.

1 kilocalorie (kcal) is equal to 1000 calories

1 kilojoule (kJ) is equal to 1000 joules

26
Q

Carbohydrates: ____ Cal/g
Proteins: ____ Cal/g
Fat: ____ Cal/g
M

A
carbs= 4 Cal/g
proteins= 4 Cal/g
fats= 9 Cal/g
27
Q
SPECIFIC HEAT (SH or c):
* definition 
* how it is written
* formula
M
A

Every substance can absorb heat and has its own characteristic ability to do so. SH is the amount of energy/heat (J or cal) required to increase 1 g of a substance by exactly 1^oC.

This temperature change is written as delta T, where the delta symbol means “a change in”

SH = heat/grams x delta T = J (or cal)/1g x 1^oC

28
Q

What is the FIRST LAW OF THERMODYNAMICS?

M

A

Conservation of Energy: the total of a closed system is a constant.

29
Q
History of the development of the PERIODIC TABLE:
* late 18th century
* 1871
* modern
M
A
  1. Late 18th century: 23 known elements. Lavoisier published table of elements organized into groups with similar chemical properties
  2. 1871: Mendeleev published, 65 known elements
  3. Modern: currently 118 known elements
30
Q
State the common MAIN GROUP name for each:
* 1A
* 2A
* 6A
* 7A
* 8A
M
A
1A= Alkali metals
2A= Alkaline earth metals
6A= Chalcogens
7A= Halogens
8A- Noble gases
31
Q

METALS:
* describe
* exception
M

A

Shiny Solids @ room temperature, good conductors (heat and electricity), malleable and ductile.

Exception: Hg (l)-mercury

32
Q

NON-METALS:
* describe
* exception
M

A

Gases or dull brittle solids

Exception: Br2 (l) Bromine

33
Q

METALLOIDS:
* describe
M

A

Properties between metals and non-metals,

semi-conductors

34
Q

What are DEGREES when measuring temperature on both the Celsius and Fahrenheit scales?

M

A

On the Celsius and Fahrenheit temperature scales, the temperature difference between freezing an boiling is divided into smaller units called DEGREES:

  • the Celsius scale has 180 degrees between the freezing and boiling points of water.
  • the Fahrenheit scale has 180 degrees between the freezing and boiling points of water.
35
Q

Describe the difference a degree Celsius and a degree Fahrenheit.

Give these equalities:

  • 1 degree C= _____ degrees F
  • 180 Fahrenheit degrees = ____ degrees Celsius

Give an equation using these equalities.

M

A

A degree Celsius is almost twice the size of a degree Fahrenheit.

Equalities:

  • 1 ^o C = 1.8^o F
  • 180 F degrees = 100 degrees C

Equation:
180 F degrees/100 degrees C = 1.8 ^oF/1^oC

36
Q

Give a temperature equation that relates a F temperature and its corresponding C temperature.

M

A

Temperature equation: TF = 1.8 (TC) + 32
(note- the T should be italicized and the F or C written lower than the T- see page 57 in chapter two of the text)

  • in this equation, the C temp is multiplies by 1.8 to change degrees C to degrees F, then 32 is added to adjust the freezing point from 0^oC to 32^oF. Both values, 1.8 and 32 are exact numbers
37
Q

Give a temperature equation to convert from Fahrenheit to Celsius

A

TC= TF - 32/ 1.8

note- the T should be italicized and the F or C written lower than the T- see page 57 in chapter two of the text

38
Q

On the Kelvin scale, how many kelvins are between the freezing and boiling point of water?

This makes a kelvin equal is size to a ______ degree.

A

Between the freezing point of water (273K) and the boiling point (373K), there are 100 kelvins, which makes a kelvin equal in size to a Celsius degree.

1K= 1^oC

39
Q

Write an equation that relates a Celsius temperature to its corresponding Kelvin temperature

A

TK = TC + 273

note- the T should be italicized and the K or C written lower than the T- see page 58 in chapter two of the text

40
Q

1 gram of water requires _______ J to increase its temperature by 1^oC

Adding the same amount of heat will raise the temperature of 1g of aluminum by about ____^oC and
1g of copper by ______ ^oC.

A

4.184 J (or 1.00 cal)

(The high SH of water has a major impact on the temperatures in a coastal city compared to an inland city, and a similar effect happens with our bodies. See page 62 in chapter 2 of the text for details)

aluminum- 5^oC
copper- 10^oC

(The low SH of aluminum and copper mean they transfer heat efficiently, which makes them useful in cookware.)

41
Q

What is the HEAT EQUATION?

A

When we know the SH of a substance, we can calculate the heat lost or gained by measuring the mass of the substance and the initial and final temperature.

Heat = mass  x temperature change  x specific heat
Heat = mass  x          delta T                x    SH
cal    = grams x            ^oC                   x  cal/g ^oC
J       = grams x            ^oC                   x  J/ g ^oC
42
Q

What are the 4 steps in calculations using SH?

A
  1. List given and needed data
  2. Calculate the temperature change
  3. Write the heat equation and rearrange for unknown
  4. Substitute the given values and solve, making sure units cancel.
43
Q

ENERGY VALUES IN NUTRITION:
* 1 Cal (with uppercase C) = _____ kcal = ______ cal

  • 1 Cal = __________ kJ = ________ J
A
  • 1 Cal = 1 kcal = 1000 cal

* 1 Cal = 4.184 kJ = 4184 J

44
Q

How is the number of calories in food determined?

A

By using an apparatus called CALORIMETER.

A sample of food is placed in a steel container filled with 02 with a measured amount of water which fills the surrounding chamber, the food sample is ignited, releasing heat that increases the temp of the water. From the mass of the food and water as well as the temp increase, the energy value of the food is calculated.

45
Q

The energy (caloric) values of food are the kilocalories or kilojoules obtained from burning _______ of carbohydrate, fat or protein.

A

1g

See page 65 in the text for examples of the calculations

46
Q

During melting, energy called the _______ __ _______
is needed to separate the particles of a solid.

Give this for water, in cal and J

A

heat of fusion

Heat of fusion for water:
80. cal/ 1 g water 334J/ 1 g water

(This is also the heat that must be REMOVED to freeze exactly 1 g of water at its freezing point (0^oC).

See page 68 in the text for how to calculate heat to melt or freeze water.

47
Q

What are the 4 steps for calculations using Heat of Fusion?

A
  1. List the grams of substance and change of state
  2. Write the plan to convert grams to heat and desired unit.
  3. Write the heat conversation factor and metric factor if needed.
    Set up the problem with factors.
48
Q

Changes of State (when matter is converted from one state to another- what are each of these called and what happens?):

  1. liquid to gas = ________
  2. gas to liquid= _______

M

A
  1. vaporization (evaporation)- water molecules with sufficient energy escape from the liquid surface and enter the gas phase. As heat is added, more and more water molecules evaporate. At the boiling point (bp) the molecules of the liquid have the energy needed to change into a gas…gas bubbles form throughout the liquid, then rise to the surface and escape.
  2. condensation- when heat is removed, a reverse process takes place. Water vapor is converted back to liquid as the water molecules lose kinetic energy and slow down. Condensation occurs at the same temperature as boiling but differs because heat is removed.
49
Q

Changes of State (when matter is converted from one state to another- what are each of these called and what happens?):

  1. solid to gas= ________
  2. gas to solid= _______

M

A
  1. sublimation- the particles on the surface of a solid change directly to a gas without going through the liquid state. (Ex: dry ice; freeze-dried foods)
  2. deposition-gas changes directly to a solid. (Ex: freezer burn)
50
Q

Give the heat of sublimation for water (in cal and J)- the energy that must be added to convert exactly 1 g of solid to vapor)

A
  1. cal/ 1 g water 2590 J/ 1 g water
51
Q

Give the heat of vaporization for water, in cal and J (the energy that must be added to convert exactly 1 g of liquid to gas at its boiling point)

A

540 cal/ 1 g water 2260 J/ 1 g water

52
Q

What are the 4 steps for calculations using heat of vaporization?

A
  1. List the grams of substance and change of state.
  2. Write a plan to convert grams to heat and desired unit.
  3. Write the heat conversation factor and metric factor if needed.
  4. Set up the problem with factors.
53
Q

What is a HEATING CURVE?

A

All the changes of state during the heating of a solid can be illustrated visually. On a heating curve, the temp is shown on the vertical axis and the addition of heat is shown on the horizontal axis.

See page 72 in the text for the diagram and steps.

54
Q

What is a COOLING CURVE?

A

A diagram of the cooling process in which the temp decreases as heat is removed.

See page 72 in the text for the diagram and steps.

55
Q

On a HEATING or COOLING CURVE, many problems require a combination of steps that include a _______ change as well as a change of ________. How are these calculations done, in general terms?

A

a TEMPERATURE change as well as a change of STATE.

The heat is calculated for each step separately and then added together to find the total energy.

See page 73 in the text for examples.

56
Q

What is the HEAT EQUATION that is used in calculations using specific heat?

A

Heat= mass x temperature change (∆T) x SH

57
Q

Give the heat of FUSION for water (in cal and J)- the energy that must be added to convert exactly 1 g of solid to liquid)

A

80.cal/1 g H2O

334 J/1 G H2O

58
Q

What are the freezing and boiling temperatures for:

  • Celsius
  • Fahrenheit
  • Kelvin
A

Freezing and boiling temperatures for:

  • Celsius (F- 0, B- 100)
  • Fahrenheit (F- 32, B- 212)
  • Kelvin (F- 273, B- 373)