Bell RingerBell Ringer

Draw the Molecule & give the Formula for:– Carbon and 2 Sulfurs– Hydrogen, Oxygen, and Chlorine– Carbon, two Chlorines, 2 Fluorines– Phosphorus, Hydrogen, Sulfur

Molecular Compounds: Molecular Compounds: Formulas & NamingFormulas & Naming

Ch 6.3b - Covalent Bonds

Describing Molecular Describing Molecular CompoundsCompounds

What information do the name and formula of a molecular compound provide? – Ionic Bonds (Ionic Compounds) -

Describing Molecular Describing Molecular CompoundsCompounds

What information do the name and formula of a molecular compound provide? – Ionic Bonds (Ionic Compounds) -

Name – Type of elements in the compoundFormula – Ratio/Number of atoms of each

element in the compound.

Describing Molecular Describing Molecular CompoundsCompounds

Covalent Bonds (Molecular Compounds)– Name & Formula - the type and

number of atoms in a molecule of the compound.

Naming Molecular CompoundsNaming Molecular Compounds

Naming Order: Step 1:

– Element farthest to the left named 1st. Most MetallicElements in the same group more metallic element

is closer to the bottom of the group. Name does not change! (just like in ionic)

– Formulas are written same way– Example:

Sulfur is named before chlorine SCl2

Naming Molecular CompoundsNaming Molecular Compounds

Exception: Oxygen & Halogens– Oxygen comes 2nd when combined with

lower-electronegativity halogens (Group 17)

– Example: ClO2 (electronegativity: Cl = 3.0; O = 3.5)

Naming Molecular CompoundsNaming Molecular Compounds

Step 2: – Second element “ide” ending (like the anion

in an ionic compound) Examples:

– Chlorine chloride– Oxygen oxide

mono - onedi - twotri - threetetra - fourpenta - five

hexa - sixhepta - sevenocta - eightnona - ninedeca - ten

Naming Molecular CompoundsNaming Molecular Compounds Step 3:

– Add prefixes to elements names to specify the number of atoms of each element in the compound.

Naming Molecular CompoundsNaming Molecular Compounds

Prefixes:• mono - one• di - two• tri - three• tetra - four• penta - five

Example:

N2O Dinitrogen monoxide

N4O5 Tetranitrogen pentoxide

Naming Molecular CompoundsNaming Molecular Compounds

CO Carbon monoxideCO2 Carbon dioxide

SO10 Sulfur decaoxide

Exception to Step 3–– Only one atom of the 1st element = NO

PREFIX!

Naming Molecular CompoundsNaming Molecular CompoundsMore Examples:More Examples:

N2Cl5 – Dinitrogen

pentachloride

N2O5 – Dinitrogen

pentoxide

P5Cl6 – Pentaphosphorous

hexachloride

SO10 – Sulfur decaoxide

Writing Molecular FormulasWriting Molecular Formulas

Step 1: – Write the element symbols (in order)

Step 2: – Prefixes values subscripts

No prefix = 1 atom (no subscript)– Only applies to 1st element in the formula

Writing Molecular FormulasWriting Molecular Formulas

Examples:– Diphosphorus Pentoxide P2O5

– Silcon Dioxide SiO2

– Carbon Tetrachloride CCl4

– Trineptunium Octoxide Np3O8

You TryYou Try

Give the formula for:– Oxygen Difluoride – Phosphorus Tribromide – Trisilicon Tetranitride

Give the Name for: – NO2

– N2O3

– SO3

You Try - AnswersYou Try - Answers

Give the formula for:– Oxygen Difluoride OF2

– Phosphorus Tribromide – Trisilicon Tetranitride

Give the Name for: – NO2

– N2O3

– SO3

You Try - AnswersYou Try - Answers

Give the formula for:– Oxygen Difluoride OF2

– Phosphorus Tribromide PBr3

– Trisilicon Tetranitride Give the Name for:

– NO2

– N2O3

– SO3

You Try - AnswersYou Try - Answers

Give the formula for:– Oxygen Difluoride OF2

– Phosphorus Tribromide PBr3

– Trisilicon Tetranitride Si3N4

Give the Name for: – NO2

– N2O3

– SO3

You Try - AnswersYou Try - Answers

Give the formula for:– Oxygen Difluoride OF2

– Phosphorus Tribromide PBr3

– Trisilicon Tetranitride Si3N4

Give the Name for: – NO2 Nitrogen Dioxide

– N2O3

– SO3

You Try - AnswersYou Try - Answers

Give the formula for:– Oxygen Difluoride OF2

– Phosphorus Tribromide PBr3

– Trisilicon Tetranitride Si3N4

Give the Name for: – NO2 Nitrogen Dioxide

– N2O3 Dinitrogen Trioxide

– SO3

You Try - AnswersYou Try - Answers

Give the formula for:– Oxygen Difluoride OF2

– Phosphorus Tribromide PBr3

– Trisilicon Tetranitride Si3N4

Give the Name for: – NO2 Nitrogen Dioxide

– N2O3 Dinitrogen Trioxide

– SO3 Sulfur Trioxide