Covalent Bonding And Lewis Dot Structures Notes Page 3
ADVERTISEMENT
1
2
3
4o Bond-dissociation Energy (Bond Energy):
Bond Energy Trends:
(1) The smaller the bond length, the stronger the bond, and the greater the bond energy
(2) A triple bond is the shortest, is the most difficult to break, and has the highest bond
energy.
(3) A single bond is the longest, is the easiest to break, and has the lowest bond energy.
The sum of the bond-dissociation energy values for all of the bonds in a molecule is the amount
of chemical potential energy in a molecule of that compound
Total energy change of a chemical reaction is determined from the energy of the ____________
broken and formed
Must _______________________ energy to ________________________ bonds
Must _______________________ energy to ________________________ bonds
Endothermic reaction
o Greater amount of energy is required to break the existing bonds in the
reactants than is released when the new bonds form in the products
Exothermic reaction
o More energy is released during product bond formation than is required to
break bonds in the reactants
Ways to Represent Covalently Bonded Molecules
o Electron-dot Structures: show valence electrons of atoms
DRAW THE ELECTRON DOT STRUCTURES FOR NITROGEN AND FLUORINE BELOW:
o Lewis Dot Structures: show arrangement of electrons in a molecule
Steps to drawing a Lewis Dot Structure:
(1) Calculate total # of valence electrons
o Ex) CO
= 4 + 2(6) = 16 valence electrons
2
(2) Determine central atom
o Usually listed first or is the least electronegative (furthest to the left on the
periodic table)
(3) Draw skeletal structure
(4) Connect every bonded pair of atoms by a dash (represents 2 electrons)
(5) Distribute remaining electrons to atoms surrounding the central atom to satisfy the
Octet Rule
(6) Distribute remaining electrons to central atom (may require multiple bonds)
ADVERTISEMENT
0 votes
Related Articles
Related forms
Related Categories
Parent category: Education