Ch. 12.1 Notes---Ionic Bonding & Ionic Compounds

Ionic Bonds

• Form when ___________ transfer their _____________ electrons to a _______________.

• The forces of attraction between the ____________ (+) and the _____________ (-) bind the compound together.

How to Represent an Ionic Bond

(1) Quantum Mechanics (electron configurations):

Na 1s2 2s2 2p6 3s1

Cl 1s2 2s2 2p6 3s2 3p5

metals valencenonmetal

cationanion

Na… ___ 3s

↑

Cl… ___ ___ ___ ___ 3s 3p

↓↑ ↑ ↑↓ ↓ ↓

How to Represent an Ionic Bond

2) Bohr Model

How to Represent an Ionic Bond

3) Electron Dot Notations:

Na + Cl [ ] [ ]

Practice Problems: (1) Draw the electron dot notation for the formation of an ionic compound between sodium and oxygen.

(2) Draw the electron configuration notation for the formation of an ionic compound between magnesium and fluorine.

Na+1 Cl -1

Valence Electrons On The Periodic Table

12 3 4 5 6 7

8

Sucktastic!Assume 2

Charges On The Periodic Table

+1+2 +3 +/-4 -3 -2 -1

0

Sucktastic!

Sodium + Chloride

Practice Problems:

3) a) Draw the electron dot notation for a potassium atom.

b) Draw the electron dot notation for a potassium ion.

(4) a) Draw the electron dot notation for a sulfur atom.

b) Draw the electron dot notation for a sulfur ion.

K

[K+1]

S

[ S -2]

Properties of Ionic Compounds and Covalent Molecules

Ionic:

•_______________ of electricity when dissolved water or melted.

•formed between __________ and _________________

•have _________ melting points

•usually ________ soluble in water

• form ___________________ solids

Conductors

metals nonmetals

high

very

crystalline

(dissolved salt)

Crystalline Patterns

Quartz• Quartz is the common mineral form of

silicon dioxide (SiO2). It is the dominant mineral in most sands and sandstones.

http://www.wegnercrystalmines.com/22/ispecials/is2.html

Pyrite

• mineral form of the iron disulfide (FeS2) with a gold-like appearance, making it also known as "fool's gold"

Gypsum

• Gypsum is a very soft mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O.

Properties of Ionic Compounds and Covalent Molecules

Molecular:

• ________________ of electricity always

• formed between two _______________

• usually have ________ melting points

• solubility in water _______: (polar =dissolve; nonpolar = insoluble)

For a compound to to conduct electricity it must have:

(1) Charged Particles (_________)

(2) Particles Free to Move (___________ or __________ phase)

Insulators

nonmetals

low

varies

ions

liquid aqueous

Demonstration

good conductor

poor conductor

nonconductor

PureH2O

great conductor

Ch. 6 Notes---Chemical Names & Formulas

• Ionic Compounds (“________”):

–Name or formula starts with a _________ (or NH4 +,

ammonium).

–Other quick ways to tell if the compound is ionic:

• formula uses parentheses

Example: ________________

• formula contains more than 2 elements (capital letters)

Example: ________________

• name uses Roman numerals

Example: ________________

• name ends in “-ate” or “ite”.

Example: _________________

salts

metal

Ca(OH)2

FeCrO4

lead(II) chloride

barium sulfate

Writing Formulas for Ionic Compounds

• Step 1-- use your ion sheet and find the ions and their charges.

• Step 2-- “Cross the charges” if they don’t balance out.

• Step 3-- Use parentheses around polyatomic ion “chunks”.

Practice Problems: Write the formula for each ionic compound.

copper(II) bromide ____________________

aluminum nitrite _________________________

barium hydrogen carbonate ___________________________

Cu+2 Br -1= CuBr2…(don’t show 1’s)

Al+3 NO2 -1 = Al(NO2)3

Ba+2 HCO3-1 = Ba(HCO3)2

Naming Ionic Compounds

• Just use your ion sheet and find the names of the ions.

cation name anion name

Practice Problems: Name the following ionic compounds.

a)NaC2H3O2 b) (NH4)2CO3 c) NaCl d) CaO

sodium acetateammonium carbonate

sodium chloride

calcium oxide