Unit 4 Part I IB Chem

Physical Properties of Ionic Compounds

• Solids are usually hard & brittle

• Typically soluble in water

• Do conduct electricity in aqueous or molten state

  • Molten = melted

  • Do NOT conduct electricity as solids

• Melting points and boiling points are usually HIGH

Ionic bonding

• Ionic bonds form between a metal & a non-metal 

• Electrons are transferred from the metal to the non-metal 

• In an ionic bond, a cation and an anion have an electrostatic attraction

• The cation is the metal, loses electrons and is a positive ion

• The anion is the non-metal, gains electrons and is a negative ion

Ionic Bonding Facts

• Large electronegativity difference 

  • >2.2 between ions

• Forms crystal lattice structure

Ionization of Sodium

• metal

• Valence Shell - 3s¹

• loses electron

• isoelectronic with Neon

• becomes Na⁺(cation)

Ionization of Chlorine 

• Chlorine

  • nonmetal

  • Valence Shell - 3s²3p⁵

  • gains electron

  • isoelectronic with Argon

• becomes Cl^- (anion)

How to write chemical formulas

• Ions have charges based on their valence electrons

• Ions combine in the smallest ratio to make a net charge of zero

• Positive charges and negative charges must cancel out.

Roman Numeral

 

Number	Roman Numeral
1	I
2	II
3	III
4	IV
5	V
6	VI

Naming Ionic Compounds with Transition Metals

• Silver (Ag) always has a 1+ charge

  • Ag⁺

• Zinc (Zn) is always 2+

  • Zn²⁺

• No roman numeral is needed for Ag, Zn, Al, group 1 and group 2

Naming Acids

• All acids have a Hydrogen in them

• All acids will start with H

Naming Monatomic Acids

• Acids with a monatomic anion

  • Use the prefix “hydro”

  • Use the name of the anion

    • but change the ending to -ic 

  • Add the word acid at the end

  • Example:

    • HBr

    • Hydrobromic Acid

Naming Acids with Polyatomic Ions

• Acids with a polyatomic ion

  • NO “hydro”

  • If the polyatomic ion ends in

    • “ate” → “ic”

    • “ite” → “ous” 

  • Add the word acid at the end

  • Example:

    • H₂SO₄

    • Sulfuric acid

Example of Ionic Compound Formula

Calcium and Fluorine

Example of Ionic Bond w/a transition metal