NOTES: INTRODUCTION TO CHEMISTRY



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|UNIT 1: Matter and Energy |

|Part A: Classification of Matter |

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|Big Picture Ideas: |

|All matter has identifiable characteristics that can be used for classification purposes. |

|All changes in matter are accompanied by a change in energy. |

|Big Picture Questions: |

|How can a substance’s properties be used to classify it and separate it from other substances? |

|How does energy govern the state and properties of matter? |

|Suggested Resources… |

|Homework Assignments |

|Classwork Assignments |

|Laboratory Activities |

|Formative Assessments |

|Textbook pages: Chapter 2 |

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|Key Terms: |

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|matter |

|solid |

|liquid |

|gas |

|plasma |

|physical property |

|chemical property |

|physical change |

|chemical change |

|law of conservation of matter |

|element |

|compound |

|pure substance |

|mixture |

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|heterogeneous mixture |

|homogeneous mixture |

|energy |

|kinetic energy |

|potential energy |

|radiant energy |

|law of conservation of energy |

|Kelvin scale |

|Celsius scale |

|Fahrenheit scale |

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|absolute zero |

|distillation |

|crystallization |

|chromatography |

|filtration |

|Directions: Use this information as a general reference tool to guide you through this unit. Don’t hesitate to ask your teacher for help! |

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|By the conclusion of this unit, you should know the |By the conclusion of this unit, you should be able to do the following: |

|following: | |

| |Define chemistry and matter. |

|Chemistry is the study of matter and the changes it can |Apply knowledge of proper laboratory safety. |

|undergo. |Classify different types of matter using a substance’s physical and chemical |

|Lab safety rules must be followed. |properties, states of matter and the physical and chemical changes the substance could|

|Matter can exist in different phases and energy changes |undergo. |

|occur during phase changes. |Describe how different separation techniques can be used to distinguish between |

|Changes in matter can be classified as either physical or |substances in a mixture. |

|chemical changes. |Classify examples of different forms of energy. |

|Separation techniques can be employed to determine the |Differentiate between temperature and heat. |

|components of a mixture. | |

|Energy exists in different forms | |

|(kinetic/potential/radiant) and can be converted from one | |

|form to another. | |

|Temperature is a measurement of the average kinetic energy| |

|of a substance. | |

|Heat is energy which travels from a hot object to a cold | |

|object. | |

Practice Problems:

Part 1: Indicate which of the following is an element (E), a compound (C), heterogeneous mixture (H), or solution (S).

1. ocean water 7. aftershave lotion

2. calcium 8. a hamburger

3. vitamin C (ascorbic acid) 9. aluminum foil

4. dry ice (solid CO2) 10. milk

5. copper 11. table salt (NaI or NaCl)

6. grain alcohol 12. iron nail

Part 2: Classify the following as a chemical property or a physical property

1. reacts with H2O 7. is ductile

2. is red 8. is flammable

3. conducts electricity 9. is 1.5 m long

4. resists corrosion 10. is malleable

5. boils at 88 oC 11. is corrosive

6. dissolves in gasoline 12. freezes at -17 oC

Part 3: Classify each as a physical change or a chemical change

1. alcohol evaporating 5. an explosion

2. a firefly (lightning bug) 6. salt dissolving in water

lighting up 7. digesting food

3. a battery charging 8. hammering hot iron into a sheet

4. ice melting 9. paper burning

INTRODUCTION TO CHEMISTRY

Chemistry-

The study of the composition of matter and the changes that matter undergoes.

Matter- anything that has mass and occupies space

States of Matter: solid, liquid, gas

Group Activity: Classification of Matter

1. Discuss the terms “element”, “compound” and “mixture” with your group. Write your definition for each in the space provided below. Include the terms “atom”, “molecule” and “chemical bond” where appropriate.

Element:

MY IDEA:

CLASS:

The simplest form of matter having a unique set of properties. Cannot be broken down into simpler substances. Found on the Periodic Table.

Compound:

MY IDEA:

CLASS:

Contains 2 or more elements chemically combined.

Mixture:

MY IDEA:

CLASS:

A blend of 2 or more pure substances not chemically combined.

A pure substance is either an element or a compound. It contains only one type of particle. A mixture contains two or more different particles.

2. Study petri dishes A-F. Each nut, bolt or washer represents an atom. Determine whether each dish contains atoms or molecules. Then determine whether each represents an element, a compound or a mixture. If it contains an element or compound, the sample is a substance. If it contains a mixture, it is not a substance.

|Petri Dish |Atom, molecule or both are present |Contents represent a(n) element, mixture or compound |

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|C | | |

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3. Use your understanding of elements, compounds and mixtures to classify each of the following:

a. hydrogen: ____element_______________ d. ammonia (NH3) __compound___________

b. sugar: _______compound_____________ e. ocean water _____mixture______________

c. orange juice: __mixture_______________ f. silver __________element______________

4. Mixtures can be homogeneous or heterogeneous. Use the examples given in class to define “homogeneous mixture” and “heterogeneous mixture”.

Homogeneous mixture:

Uniform composition. Components evenly distributed and not easily distinguished.

Heterogeneous mixture:

Not uniform composition. Components unevenly distributed throughout mixture.

CLASSIFICATION OF MATTER HOMEWORK

Determine whether each example or property below is a pure substance. Then label each as an “element” (E), “compound” (C), homogeneous mixture (HO) or Heterogeneous Mixture (HE). Use your own examples to complete the chart.

|Pure Substance? |Example |E, C, HO or HE? |

|N |sand |HE |

|Y |salt |C |

|Y |pure water |C |

|N |tap water |HO |

|Y |aluminum |E |

|Y |gasoline |HO |

|N |soda |HE |

|N |an egg |HE |

|Y |sugar |C |

|Y |copper |E |

|N |steel |HO |

|Y |nitrogen |E |

|N |air |HO |

|N |particles combine in any proportion |HO |

|N |appears like one substance, but shows two different boiling points |HO |

|Y |only separable by a chemical reaction |C |

|N | |homogeneous mixture |

|Y | |element |

|Y | |compound |

|N | |heterogeneous mixture |

MATTER, PHYSICAL/CHEMICAL PROPERTIES & CHANGE

States of Matter:

| |SOLID |LIQUID |GAS |

|SHAPE | | | |

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| |Definite |Of container |Of container |

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|VOLUME | | | |

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| |Definite |Fixed |Of container |

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|PARTICLES | | | |

| |Close-packed |Close-packed | |

| |Ordered |Disordered |Far apart |

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|MOTION | | | |

| |Vibration. | | |

| |No translation (from place to place) |Flows |Flows |

CHEMICAL AND PHYSICAL PROPERTIES

Properties of Substances A and B. List your observations and we will classify as physical or chemical properties.

|SAMPLE A |SAMPLE B |

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KEY WORDS

● substance unchanged ● substance changes when ● chemical composition ● identity of substance

● color measured unchanged changes

● odor ● flammability ● bend ● bake

● temperature ● reactivity ● break ● burn

● density ● toxicity ● dissolve ● cook

● texture ● acid or base ● phase change (boil, melt, etc.) ● rust

● mass ● ● rip ● react

● luster (shine) ● ● crystallize ● tarnish

● hardness ● ● ● decompose

● melting/boiling-point ● ● ●

Physical Property:

Something that is observable and measurable without changing the substance (chemical composition). E.g. color, mass, temperature, density, texture, shape.

Chemical Property:

The ability or inability of a substance to combine with or change into one or more new substances. You must change the substance (chemical composition) in order to make the observation. E.g reactivity, flammability, toxicity.

Identify the following as Physical or Chemical Properties:

the pigment is blue ______P__________

sodium reacts violently with water ______C__________

wax melts at 82 °C ______P__________

iron rusts when left out in the rain ______C__________

oil floats on water ______P__________

Physical Change:

Can be reversible or irreversible. Nothing new is made. The chemical identity does not change. The arrangement, location or speed of particles may change. E.g. rip, melt, freeze, boil, condense, dissolve.

Chemical Change:

The identity of the substance changes and something new is made.

Evidence: bubbles, color change, temperature change, light, heat, smoke.

e.g. reacts with, burns, tarnish

Identify the following as Physical or Chemical Changes:

CO2 is released when Alka Seltzer is added to water ______C__________

salt dissolving in water ______P__________

baking cookies ______C__________

burning coal ______C__________

PHYSICAL VS. CHEMICAL HOMEWORK

Label each property below as physical (P) or chemical (C):

__C__ 1. moth balls vaporize in the closet _P___ 6. butter melts at 30 °C

__C__ 2. hydrofluoric acid attacks glass _P___ 7. sugar dissolves in water

__P__ 3. chlorine gas liquefies at -35 °C _P___ 8. paint dissolves in acetone

__C__ 4. hydrogen gas burns in chlorine gas _C___ 9. baking soda fizzes with acid

__P__ 5. hydrogen gas pours “up” because it is lighter than air

Determine whether each change below is physical (P) or chemical (C).

__P__ 1. perfume evaporating on your skin __C__ 5. wood rotting

__C__ 2. autumn leaves changing color __P__ 6. melting copper metal

__C__ 3. burning sugar __C__ 7. baking a cake

__P__ 4. fogging a mirror with your breath __P__ 8. slicing potatoes for fries

Classify each term below as physical (P) or chemical (C).

__P__ 1. boil __P__ 6. Melt

__C__ 2. burn (combustion) __C__ 7. Bake

__P__ 3. evaporate __C__ 8. Tarnish

__P__ 4. dissolve __C__ 9. React

__C__ 5. rust __P__ 10. Freeze

Physical/Chemical Properties/Changes

I. Fill in the Blanks

_Physical____________ properties can be observed without chemically changing matter. ____chemical_____________ properties describe how a substance interacts with other

substances. ____Solids_____________ have definite shapes and definite volumes.

___Liquids______________ have indefinite shapes and definite volumes. _____Gases____________ have indefinite shapes and indefinite volumes.

Phase changes are ___physical______________ changes. ___Freezing______________ point is the temperature at which a liquid turns to a solid. It is also equal to the ___melting______________ point which is the temperature at which a __solid__________ turns to a ____liquid_____________. ___Boiling______________ point is the temperature at which a liquid turns to a gas, and __condensation_______________ point is the temperature at which a gas turns to a liquid. Occasionally, a solid turns directly into a gas without turning into a liquid first. This is called _sublimation____.

II. Label these properties as chemical (C) or physical (P). Be certain to know the definition of each of these properties.

__C___combustibility __P___density __P___malleability

__C___tendency to corrode __C___failure to react __P___melting point

__P___ductility __P___odor __P___texture

__C___flammability

III. Label these changes as chemical (C) or physical (P).

__C___digestion of food __C___explosions __P___getting a haircut

__C___lighting a candle __P___evaporation __C___tarnishing silver

__P___ice cube melting __C___formation of acid rain

__P___crushing rocks __P___dissolving salt in water

● smallest particle = atom ● smallest particle = molecule ● uniform composition ● not uniform

● cannot be separated or ● atoms are chemically bonded ● cannot see different parts composition

broken down into simpler ● composed of more than 1 kind of atom ● aka solution ● can see different parts

substances by chemical means ● can be broken down chemically ● e.g. gasoline ● e.g. muddy water

● unique set of physical and ● properties are very different from ● syrup ● salad

chemical constituent elements ● iced tea ● OJ

● represented by a symbol on ● alloys (such as steel) ● milk

the Periodic Table ● air ● blood

SEPARATION OF COMPOUNDS AND MIXTURES

SEPARATION OF MIXTURES VOCABULARY

1. filtration

2. crystallization

← Solid dissolved in water

← Evaporate water

← Can be used for homogeneous mixture

3. chromatography

4. distillation

SEPARATION OF COMPOUNDS AND MIXTURES PRACTICE

1. sand, salt and water

1. filter (removes sand)

2. evaporate (removes water)

2. coffee and water

evaporate (removes water)

3. iron filings and sulfur

magnet (removes iron)

4. salt and pepper

1. rub a plastic ruler with wool

2. hold the ruler close to the salt and pepper

3. the pepper will stick (the ruler is negative from gaining electrons from the wool, and the pepper becomes positive)

5. hydrogen and oxygen in water

electrolysis. Using a battery, hydrogen is formed at the cathode (negative) and oxygen at the anode (positive)

6. C from H and O in sugar (demonstration)

Sugar is dehydrated: C12H22O11 ( 12 C + 11 H2O

MATTER & ENERGY

Energy: The ability to do work or produce heat

potential energy: stored energy

examples: high object, battery, chemical bond, string of a bow

kinetic energy: due to motion

examples: falling rock, turning wheel

Units of Energy: joule (J) or calorie (cal)

Temperature: A measure of the average kinetic energy of particles in matter. It determines the direction of heat flow.

Units:

Celsius: oC

Kelvin: K (K = oC + 273)

Absolute zero: The zero point on the Kelvin temperature scale, or -273 oC. At this theoretical minimum temperature, matter has no energy.

Law of Conservation of Energy:

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Law of Conservation of Matter: In any chemical or physical process, matter is neither created nor destroyed

Example: Mg + oxygen ( ash

_____ + _____( ________

a. If 10.0 g of magnesium metal burns in air, and reacts with 6.6 g of oxygen, what mass of ash will form?

10.0 + 6.6 = 16.6 g

b. If 25 g of magnesium metal burn in air, 41.5 g of ash are formed. What mass of oxygen reacted with the magnesium?

41.5 -25 = 16.5 g

Try: sodium (Na) reacts with potassium chloride (KCl) to produce potassium (K) and sodium chloride (NaCl).

Na + KCl ( NaCl + K

_20__ _30___ ( __x___ _15___

If 20 g of sodium (Na) reacts with 30 g of potassium chloride (KCl) and 15 g of potassium (K) are produced, find the mass of sodium chloride (NaCl) also produced.

20 + 30 = x + 15

So x = (20 + 30) – 15 = 35 g

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Measureable/

Observable

An action performed on the substance

Properties

and

Changes

CHANGES

PROPERTIES

PHYSICAL

Use your senses

CHEMICAL

Ability to combine or react

CHEMICAL

PHYSICAL

Reversible or irreversible

Anything that has MASS

&

Takes up space (has VOLUME)

MIXTURES

More than 1 type of particle

Not chemically bonded

Combine in any proportion

SUBSTANCES

1 type of particle

“pure” substance

Classification of Matter

element

compound

heterogeneous

homogeneous

← Only works on heterogeneous mixtures

← Solid gets trapped in solid

← Chromo = color

← Separate colors

← Colors have different densities

← Can be used in homogeneous mixtures

← Can separate liquids with

different boiling points

In any chemical or physical process, energy is neither created nor destroyed.

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