UNIT 2: THE NATURE OF MATTER

2-1 Properties of Matter:

Some Vocabulary:QUALITATIVE info. is NON-NUMERICAL info.

tall, short, normal, heavy, good, bad, etc.

QUANTITATIVE info. is NUMERICAL info. 5’ 10’’, 110 lb, 100%, 32.5g, etc.

OBSERVATION: qualitative info. collected through use of our senses

INTERPRETATION (inference): an attempt to put meaning into an observation

DESCRIPTION: a list of the properties of something

DATA: experimentally determined quantitative info.

EXPERIMENT: a procedure carried out in order to discover a result.

-Read pages 41-42 for an overview of the differences between hypotheses, theories and laws.

Q: 1 – 12

The Physical Properties of Matter

MATTER: anything that has mass and occupies space.

SUBSTANCE: something with a unique and identifiable setof properties.

PHYSICAL PROPERTY: density, colour, hardness, melting temperature, etc.

EXTENSIVE PROPERTY: depends on the amountof the substance present.

Eg.

INTENSIVE PROPERTY: depends solely on the nature of the substance.

Eg.

CHEMICAL PROPERTY: ability of a substance to undergo chemical reactions. Eg. some burn in air, some dissolve in water, etc.

Q: 13-15

KINETIC MOLECULAR THEORY OF SOLIDS, LIQUIDS, AND GASES.

In your notes, draw a picture showing the molecular arrangement in each of these 3 states.

Solids: - don’t readily change their shape- very small changes in volume as a result of heat or pressure.

Liquids: - conform to shape of containers- slight changes in volume as a result of heat or pressure.

Gases: - conform to shape of containers- drastic volume changes as a result of heat or

pressure

DEFINITIONS OF SOME PHYSICAL PROPERTIES:Hardness – the ability of a solid to resist abrasion or

scratching

Malleability – the ability to be rolled or hammered into thin sheets

Ductility – the ability to be stretched or drawn into wires

Lustre – manner in which a solid surface reflects light.

Eg., metallic, glassy, oily, pearly, dull,

Viscosity – the resistance of a fluid to flow

Diffusion – movement of molecules from an area of high concentration to low concentration. Results in an intermingling of fluids.

Vapour Pressure (VP) – the pressure created by the vapour evaporating from a liquid.

Q: 16 – 20

(Q: 21 – 32 are extra practice, try some of these if you want the extra practice)

Phase Changes

Chemical Change – new substances are formed

Physical Change – no new substance is formed, only the phase changes.

IMPORTANT!! The amount of heat involved in a physical change is much less than

the amount involved in a chemical change.

The Role of Kinetic Energy in Physical Changes

3 TYPES OF KINETIC ENERGY:

A. Rotational (EROT)

B. Vibrational (EVIB)

C. Translational (ETRANS)

PRACTICAL APPLICATIONS OF KINETIC ENERGY CHANGES

Read through the examples in the book. Be prepared to describe one of the examples for a test.

THE ROLE OF KINETIC ENERGY IN PHASE CHANGES

Q: 64 - 71

2-2 The Classification of Matter:

SYSTEM – the part of the universe being studied

PHASE – any part of a system which is uniform in both its composition and properties

Type of Solution Examplegas – in – gas airgas – in - liquid soda pop

liquid – in – liquid water and alcoholsolid – in - liquid salt watersolid – in - solid alloys (metals melted together)

SOLVENT – the component in a solution which exists in the greater quantity

AQUEOUS SOLUTIONS – solutions in which the solvent is Water

SOLUTE – the component in a solution which exists in the smaller quantity.

IMPORTANT: When water exists in a solution, even if it is the lesser quantity, it is conventional to call water the solvent.

Let’s look at the difference between elements and compounds…If a single particle is a/an: Then a large-scale, visible collection of

these particles is called:atom

ormolecule made of identical atoms

element

molecule made of different atoms compound

IN SUMMARYPure Substance – uniform, unchanging physical

properties

Homogeneous mixture – changeable composition, but each particular composition has unchanging, uniform physical properties.

Heterogeneous mixture – each component presenthas different physical properties, regardless of composition.

Q: 33 – 44

2-3 Separating Substances of a Mixture:

A. HAND SEPARATION applies to mechanical mixtures only also includes use of sieve or magnet

B. FILTRATION mechanical mixtures separates liquids from solids material remaining on the filter paper is called the residue, while

the liquid which passes through is called the filtrate.

C. EVAPORATION solid-in-liquid solutions liquid boils away, leaving behind the solid.

D. DISTILLATION separation of liquid-in-liquid solutions

E. SOLVENT EXTRACTION 2 ways this method can be used

1. Extraction of a solid from a MECHANICAL MIXTURE of solids.

- A liquid is used that dissolves some solids but leaves others behind.- The desired solid is either dissolved, removed, and reformed

through evaporation OR- Left behind when the unwanted solid is dissolved and

removed.o Eg. Removing sugar from sand.

2. Extraction of a dissolved liquid or solid from a LIQUID SOLUTION.

Miscible – 2 liquids are soluble in each other in all proportions.

Immiscible – 2 liquids are insoluble in each other.

In order to carry out solvent extraction, a solvent must possess 2 important properties.

1. the added solvent is IMMISCIBLE with the solvent already present.2. the added solvent dissolves one or more desired substances from the

solution and leaves unwanted substances behind (or vice versa)

Process carried out in a SEPARATORY FUNNEL.

If 80% of a desired substance is removed after each extraction process, how much is removed after the process is repeated 3 times?

In this case you calculate the amount left, NOT the amount removed! After 1 extraction, 20% remains. After 2 extractions, 20% of that

20% remains. % remaining = 0.20 x 0.20 x 0.20 = 0.8%

0.8% is remaining, therefore (100 – 0.8 = 99.2%), so after 3 extractions, 99.2% has been removed.

F. RECRYSTALLIZATION solid in a solid-in-liquid solution is removed in a pure, crystallized

state.

Saturated Solution – a solution that has dissolved as much of the solid as possible.

A saturated solution of a desired solid is prepared. The saturated solution is allowed to cool, and some of the solvent

evaporates there is no longer enough solvent to keep all the solid dissolved.

The solid comes out of solution as crystals. Crystals are separated by either hand separation (for large

crystals) or filtration (for smaller crystals)

G. GRAVITY SEPARATION separate solids from a mechanical mixture based on gravity.

Eg. gold pans, mechanical shakers, etc.

commonly use a centrifuge.

Precipitate – a solid formed in a liquid solution as a result of a chemical reaction.

H. PAPER, COLUMN, & THIN LAYER CHROMATOGRAPHYseparate small amounts of solid-in-liquid solutions which are coloured.

Paper or Thin Layer Chromatography

Developing solvent – liquid which is absorbed up the sheet, dragging and depositing the solids.

Solvent front – line showing how far the developing solvent has traveled up the sheet.

Column Chromatography

- tube packed with material called the “stationary phase”

- mobile phase – solution containing mixture of dissolved solids

- developing solvent – liquid which moves through the column, dragging and depositing the dissolved solids.

Q: 45 – 58

2-4 Names and Formulas of Inorganic Compounds:Identify the following on your periodic table:

Metals Non-metals

____________ form positive ions____________ form negative ions____________ = ion with a NEGATIVE charge____________ = ion with a POSITIVE charge

Writing the Formula for Ionic Compounds1. Write the formula for the positive ion first and the negative ion second2. “Swap and Drop” the charges, turning them into subscripts3. Reduce anything that you can reduce!

Practice:1. Potassium oxide

2. Calcium phosphide

3. Tin (IV) sulphate

4. Iron (II) phosphate

5. Ammonium dichromate

6. Copper (I) phosphate

Naming Ionic Compounds- Metal ions often have more than one charge. How do you decide which

charge to use?

1st – Remember that negative ions only have ONE possible charge.- There are now 2 possible situations you could face:

1. The metal only has one possible ion charge:o Write the name of the metalo Write the name of the negative ion

remember to change the ending to –ide if it isn’t a polyatomic ion!

2. The metal is multivalent (i.e. has more than one possible ion charge)o Determine which ion charge was used (either by un-swap and drop

or by the teeter-totter method)o Write the name of the metal followed by it’s ion charge in roman

numeralso Write the name of the negative ion

Remember to change the ending to –ide if it isn’t a polyatomic ion!

Practice:1. Ag2SO4

2. Cu2O

3. FeS

4. Mg(HSO3)2

5. Al(OH)3

H2SO3 = ____________________

H3PO4 = ____________________

HNO3 = _____________________

HNO2 = _____________________

CH3COOH = _________________

6. Sr3N2

Naming Hydrates- Hydrates are ionic compounds with water molecules trapped within their

crystal structure. Their names indicate how much water is trapped.

Name the ionic compound1. Use the appropriate prefix for the # of water molecules present2. Add the word “hydrate” after the prefix

Eg. CuSO4·5H2O

Pg. 73 # 6,7

Naming Covalent Compounds- Covalent compounds are made up of 2 types of NON-METALS bonded

together1. Prefix of first element **2. Name of first element3. Prefix of second element4. Name of second element with –ide ending

** if there is only one of the 1st element, DON’T use mono, use no prefix at all.Eg. Si2I6

Pg. 74 #8,9Naming Acids:

- There are 10 common acids that you are expected to know the name sand formulas for:

HF = _______________________

HCl = ______________________

HBr = ______________________

HI = ________________________

H2SO4 = ____________________

Summary Practice Assignment:

Pages 75 – 76 #14 – 163 (do as many as you need to do to feel confident with naming and writing formulas for all types of compounds)