Structural Formulas AGENDA: Review Check homework Notes on Structural Formulas Homework: Drawing Formluas

Iron (II) oxide FeO

Carbon monoxide CO

Sodium nitrate NaNO 3

Carbon dioxide CO 2

Na + Sodium ion

Carbon tetrachloride CCl 4

Mg 3 (PO 4 ) 2 Magnesium phosphate

SiF 4 Silicon tetrafluoride

Magnesium chlorate Mg(ClO 3 ) 2

SO 2 Sulfur dioxide

Cl - Chloride

SO 3 Sulfur trioxide

ClO 3 - chlorate

Boron trichloride BCl 3

Sodium chloride NaCl

Germanium tetrafluoride GeF 4

CaCO 3 Calcium carbonate

Aluminum sulfide Al 2 S 3

NI 3 Nitrogen triiodide

(NH 4 ) 2 CrO 4 Ammonium chromate

Iron (II) ion Fe +2

carbonate CO 3 -2

H2OH2O Dihydrogen monoxide water

CoBr 2 Cobalt (II) bromide

Na 2 CO 3 Sodium carbonate

Oxide O -2

H2SH2S Dihydrogen monosulfide

Li 3 PO 3 Lithium phosphite

Barium hydroxide Ba(OH) 2

Na 2 SiO 2 Sodium silicate

Homework Check

Structural Formulas Date:

Determining the # of bonds Depends on the number of valence electrons, and whether it is easier to gain or lose e -.

FamilyValence e - # bonds Alkali11 Alkaline earth22 Boron family33 Carbon family44 Nitrogen family53 (or 4) Chalogens62 Halogens71 Noble Gases80

Advice for building structures Count total number of valence e -. Place atom that can form the most bonds in the center Place remaining elements around, spreading the evenly over the 360 o. Fill the octet of each element w/ lone e - H only needs 2 e - to fill first orbital. The first 3 columns never fill get an octet because they give their e - away. If # e -, used is more than # available, redraw using a double or triple bond.

Types of Structures Linear, 2 elements Trigonal planar, 4 elements Tetrahedral, 5 elements “star”, 6 or 7 elements

Linear Structures If 2 atoms combine, they bond in a linear fashion. F 2, fluorine Valence e -

Oxygen, O 2 Valence e -

Nitrogen, N 2 Valence e -

Trigonal Planar 4 elements combining, form the shape of a triangle using outer elements. Boron trichloride, BCl 3 Valence e -

Sulfur trioxide Valence e -

Tetrahedral 5 elements bonded, form the shape of a cross or X. Carbon tetrachloride, CCl 4 Valence e -

Sometimes the central atom has a lone pair, but still forms the basic tetrahedral Ammonia, NH 3 Valence e -

Occasionally the central atom has 2 lone pairs. Water, H 2 O Valence e -

Octet Breakers Sometimes nonmetals don’t share their e -, but instead give them all away. The central atom then has over 8 e -, starts putting the e - into the d orbital! phosphorus pentafluoride Valence e -

Sulfur hexafluoride, SF 6 Valence e -