Reminder…

4p 5p

cation anion

cation anion

Chapter 3 – Ionic & Covalent (molecular) Compounds Learn how to identify and write the names of…

Memorize these Charges on Ions in Groups 1A, 2A, 5A-7A The charge varies for particular transition metal atoms, so roman numerals must be used. The charge can be determined by simple math. Memorize common exceptions: Ag +, Zn 2+, Cd 2+, Ni 2+, Al 3+

The total number of positive charges must equal the total number of negative charges. –AlCl 3 is aluminum chloride –LiBr is lithium bromide –Ag 2 S is silver sulfide –MgO is magnesium oxide –KCl is potassium chloride

For systematic names, use Roman numerals to show charge on the metal ion –CuO is copper(II) oxide –Cu 2 O is copper(I) oxide –FeO is iron(II) oxide –Fe 2 O 3 is iron(III) oxide

EOC

–NaNO 3 is sodium nitrate. –CaCO 3 is calcium carbonate. –NaH 2 PO 4 is sodium dihydrogen phosphate. –NH 4 OH is ammonium hydroxide. –FeCO 3 is iron(II) carbonate. –Fe 2 (CO 3 ) 3 is iron(III) carbonate. –CuSO 4 is copper(II) sulfate.

–lithium ion and bromide ion form LiBr –barium ion and iodide ion form BaI 2 –aluminum ion and sulfide ion form Al 2 S 3 –sodium ion and bicarbonate ion form NaHCO 3 –potassium ion and phosphate ion form K 3 PO 4

Molecular compound:Molecular compound: a compound in which all bonds are covalent. Naming binary molecular compounds: –prefixes “di-”, tri-”, etc. are used to show the number of atoms of each element; the prefix “mono-” is not used for the first atom, i.e. carbon monoxide –NO is nitrogen monoxide (nitric oxide) –SF 2 is sulfur difluoride –N 2 O is dinitrogen monoxide (laughing gas)

1. Determine the number of valence electrons in the molecule. 2. Determine the arrangement of atoms in the molecule. 3. Connect the atoms by single bonds. 4. Show bonding electrons as a single line; show nonbonding electrons as a pair of Lewis dots. single bond double bondtriple bond 5. In a single bond, atoms share one pair of electrons; in a double bond, they share two pairs, and in a triple bond they share three pairs.

Examples –draw a Lewis structure for hydrogen peroxide, H 2 O 2. –draw a Lewis structure for methanol, CH 3 OH. –draw a Lewis structure for acetic acid, CH 3 COOH.

The “green sheets” Links & Lone Pairs

Draw Lewis Structure & Predict Polarity :