Introductionto

Chemistry

Chapter 11

Student Learning Objectives

• Distinguish between physical & chemical properties

• Classify, compare, name, & identify

chemical quantities

• Recall properties of solubility

• Apply trends in the periodic table.

What is chemistry?

Chemistry is the study of microscopic properties.

Chemical properties

“Invisible”

How and why atoms combine into molecules

What are some physical and chemical properties?

Physical Properties(Macroscopic)

• Density• Phase

• Appearance• Size 

Chemical Properties(Microscopic)

• Atomic make-up• Structure• Reactivity

Practice

1) How many different medicines exist for pain relief?

2) Is surface tension a microscopic or macroscopic property of matter?

3) What does the image show?

Is it an example of a physical

or chemical property?

More Practice

4) Name the macroscopic properties of water.

5) Name the microscopic properties of water.

6) How do carbon dioxide (CO2) and water (H2O) compare and contrast?

Some ChemicalChange Indicators

The primary difference between a physical change and a chemical change is that a chemical change produces a new substance.

Color change

Production of a Gas

Temperature Change

Light

Sound

How are elements, molecules, compounds& mixtures defined?

Question: What are the origins of the elements?

Element all of one type of atom

Molecule atoms in a chemical bond

Chemical bond attraction between atoms

Molecular Formula relative numbers of atoms in bond

A compound contains two or more types of atoms.

Type Number of Atoms

Diatomic 2Triatomic 3Polyatomic 4+

Practice

1) Which is not a compound?

2) How many atoms are contained in each?

3) Classify as diatomic, triatomic, or polyatomic.

H2O CaF2 NH3 O2

Classifying Mixtures

A substance that is pure has only one type of element, or molecule, present.

CopperSalt

A mixture contains two or more distinct types of substances (atoms/molecules).

Homogeneous Mixture

Same uniform appearance and composition throughout

Solution

(same phase)

Heterogeneous Mixture

Consists of visibly different substances and/or phases

Suspension

(particles settle)

Practice: Classify Each Substance

7-up

Aluminum

Homogenized milk

Raw milk

Oil and water

Carbon monoxide

Distilled water

Air

Tap water

How can mixtures be separated?

Water may cross a semi-permeable

membrane. (Osmosis)

Osmosis: from less to more concentrated

Reverse osmosis: from more to less concentrated

Filtration separate liquids and solids

Distilation separate gasses, liquids, solids

Desalination combines distillation and reverse osmosis

Question

Why are distillation and desalination typically not used to obtain fresh water from salt water?

What is solubility?

Solubility is a measure of how much solute will dissolve in a solvent to produce a stable solution.

Water & Sugar

Solvent (larger amount) Does the dissolving

Solute (smaller amount) Dissolves

Oil & Water

Liquids may be miscible or immiscible.

(mix or not mix)

Solubility is variable.

• Bond Strength• Bond Types• Temperature• Pressure• Molecular attractions

Solubility has a limit, based on each individual substance and physical conditions.

Concentrated

Dilute

Saturated

Concentration = Grams Liter

Practice1) If you cannot dissolve anymore sugar in your coffee,

your coffee is?

2) What is the concentration when 5 grams of sugar is added to ½ a liter of water?

3) If you have 30 mL of 25% HCl solution, how many grams of HCL are in the solution?

What are the basic trends in the periodic table?

The periodic table is periodic!

Most of the elements in the periodic table are metals.

ShinyOpaque

Good Conductors

Trends

• Chemical reactivity decreases L R

• Radius decreases along a period L R

• Ionization energy increases along a period L R

Practice

1) Which metals are liquid under normal atmospheric conditions?

2) Which of the following would be most reactive?

a. O b. He c. Al d. Cl

3) Which of the would have the smallest radius?

a. Al b. Cl

Atomic Periods (rows) are periodic. 

Atomic Groups (columns) have similar trends.

1 amu = 1.661 x 10-24 grams

Group Name AttributesIA Alkali Metals Highly ReactiveIIA Alkali Earth Metals

Middle Transition Metals High Melting PointIIIA Metalloids Metals/ Non-metalsVIA Ore Forming ElementsVIIA Halogen Gases Salt Forming ElementsVIIIA Noble Gases Non-Reactive

Emerald is a variety of beryl, a mineral that contains the

alkaline earth metal beryllium.

Lanthanides (58-71): found in geologic zones

Actinides (90-103): most are synthesized in labs

A Uranium Rock

Practice

1) In which group are the precious metals?

2) List all attributes of Bromine (Br) that can be determined using the periodic table.

What does the shell model indicate?

No two electrons can have the exact same energy state. (Pauli Exclusion Principle)

Electrons are arranged in particular orbitalsEach electron has its own set of quantum numbers (n,l,ml, ms)

which determine the energy state of the electron

Atomic period indicates the number of main energy shells available in the ground state.

Shell Maximum e-

Allowedn = 1 2n = 2 8n = 3 8n = 4 18n = 5 18n = 6 32n = 7 32

Practice

Draw the electron configuration for each atom. (Assume atoms in ground state)

1. N 2. Kr 3. Mg 4. O

Electrons attempt to have configurations that match those in group VIIIA. (Octet Rule)

Valence electrons are what make the physical and chemical properties of the atoms in a group similar.

8 − Group Number = Number Unpaired e–

Valence Electrons

More unpaired electrons = more reactive

Unpaired valence electrons are used to form chemical bonds

What are some rules for naming compounds?

Compounds

Metal is named first and then the Non-metal

NaCl = Sodium Chloride HF = Hydrogen Fluoride

Prefixes

CO2 = Carbon Dioxide

1. Mono2. Di3. Tri4. Tetra5. Penta6. Hexa7. Hept8. Oct

“Left” then “Right + ide”

Polyatomic Ions

Polyatomic Ions are molecules made up of two or more atoms that are considered an ionic group, that have charge.

1. Name the cation (+ ion) first

2. Name the anion (- ion) second + ate

CaCO3 Calcium Carbonate

PracticeWhat is the chemical name?

Does it have a common name?

1. O2 5. SF6

2. H2O 6. CH4

3. KBr 7. NH3

4. O3 8. PCl5

Practice with Polyatomic Ions

What is the chemical name?

Does it have a common name?

1. AlPO4 4. Fe(NO3)2

2. Cu2SO4 5. NaHCO3

3. KClO3 6. NaH2PO4