covalent bonding
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Covalent Bonding. Ms. Keller WTHS Chemistry. General Covalent- ness. Covalent bond - bond that results from the sharing of valence electrons. Diatomic molecule: elements that are bonded to itself in nature Br I N Cl H O F. General Covalent stuff con’t. Types of bonds: - PowerPoint PPT PresentationTRANSCRIPT
Covalent Bonding
Ms. KellerWTHS Chemistry
General Covalent-nessCovalent bond- bond that results
from the sharing of valence electrons
Diatomic molecule: elements that are bonded to itself in nature
Br I N Cl H O F
General Covalent stuff con’t
Types of bonds: Single = sigma bond Double = sigma bond + pi bond Triple = sigma bond + 2 pi
bonds
Bonds are electron pairs that are being sharedLone Pairs- unshared pairs of electrons
Lone pair
Bond LengthsBond Length- distance between the
nuclei of the 2 atoms that are bonded when they are the most attracted to one another
Determined by:◦Size of the atoms◦How many electron pairs are shared
(how many bonds there are) As # of bonds , the bond length
Energy and BondsBond dissociation energy- amount
of energy needed to break a specific covalent bond
Breaking bonds ALWAYS requires the addition of energy
Endothermic vs. Exothermic
Naming Binary Molecular Compounds!
1st element + 2nd element with the ending -ide
Use the following prefixes to indicate the number of the atoms of each element present:1. mono 6. hexa2. di 7. hepta3. tri 8. octa4. tetra 9. nona5. penta 10. deca
Naming Acids!Binary method:
◦1. prefix = hydro (to represent hydrogen)
◦2. root of 2nd element◦Change ending to –ic acid
◦Ex) HF = hydrofluoric acid
Naming Acids!Oxyacids: Acids that contain oxygen
Don’t put Hydro in for hydrogen!If the group ends in –ate, it changes to –icIf the group ends in –ite, it changes to –ousATE –IC, ITE –OUSThrow acid on the end
Ex) H2SO4 = Sulfuric AcidEx) H2SO3 = Sulfurous Acid
Let’s Practice Naming…C2O4
NO2
C4H10
SO3
N2O5
HClHBrH3PO4
HClO2
Writing FormulasJust read the name! The prefix tells you how many of
each element you have – this is your subscript!
◦Ex) carbon tetrafluoride = CF4
Because tetra=4 and it’s attached to fluorine, it becomes the subscript
How to Draw Lewis Structures for Covalent Bonding
1. Add up all valence electrons
2. Add up all octets that need to be filled (octet=2 for H)
3. Subtract step 1 from step 2
4. Divide value from step 3 by 2 to get how many bonds are in the molecule
Ex) CH4
How to Draw Lewis Structures for Covalent Bonding
Some hints for how they fit together:
Element closest to the left is usually the central atom
Hydrogen is always terminal (on the end)