AP Chem. Ch.8-9 Flashcards
Driving force among all types of bonding?
Electrostatic
Which are the three basic types of bonds?
Ionic
Covalent
Metallic
- electrostatic attractions between ions
- metal w/ nonmetal
Ionic bond
- sharing of electrons
- nonmetal w/ nonmetal
Covalent bond
-metal atoms bonded to several other atoms
Metal w/ metal
Metallic
All chemical bonds form b/c the electron-proton attraction _______ the potential energy of the system as the bond forms
Lowers
Balance between the attractiobs of the oppositely charged particles and repulsions of the like charged particles
Distance between the bonded particles
Electrons involved in bonding
Balance electrons
Where are balance electrons found?
In the incomplete, outer most shell of an atom.
Atoms tend to gain, lose, or share electrons until they are surrounded by eight valence electrons
Octet rule
Which subshells does an octet consist of?
S^2, P^6 subshells
- Energy required to completely separate a mole of a solid ionic compound into its gaseous ions.
- increases with the CHARGE on the ions.
- increases w/ the DECREASING SIZE of ions.
Lattice energy
What 2 factors affect lattice energy??
Charge and size
Thermodynamic cycle that analyzes lattice energy precisely.
Born-harber cycle
Three electrostatic interactions in covalent bonds:
- Attraction between electrons and nuclei
- repulsions between electrons
- repulsions between nuclei
Sharing of 1 pair of e- bettwen atoms.
Single covalent bond
Pair of electrons that is not being shared.
Unshared pair
Which atoms can form multiple bonds??
C, N, O, S
Sharing of 2 pairs of e- between atoms.
Double covalent bond
Aharing of 3 pairs of electrons between atoms.
Triple covalent bond
Equal sharing of electrons.
Nonpolar covalent
Unequal sharing of electrons
Polar covalent
The ability of atoms in a molecule to attract electrons to themselves
Increases accros the period, decreases down a column
Electronegativity
Representations of molecules shoeing all electrons, bonding and nonbonding
Lewis structures
How to find formal change
- count # of valence electrons
- add up the number of unshared electrons to half the number of shared electrons.
- subtract this value from the # of valence electrons.
Which are the 3 types of ions that dont follow the octet rule?
- ions or molecules with an odd number of electrons
- ions or molecules with less than an octet
- ions or molecules
How many bonds does H need to b stable?
1 bond( 2 electrons)
How many bonds does Be need for it to b stable??
2 bonds( 4 electrons)
How many bonds does B need for it to be stable??
3 bonds( 6 electrons)
Atoms from the ____ period(and below) can accomodate more than an octet.
Third. _ _
Ex: PCl5, SF4, AsF6 , and ICl4
The strength of a bond is measured by determining how much energy is required to break the bond.
Bond enthalpy
Why are the average bond enthalpies of covalent bonds positive??
B/c bond breaking is an endothermic process
Bond forming should be _____
Exothermic
As number of bonds increases…
The bond length decreases
The bond enthalpy increases
What factor plays an important role in the molecule reactivity?
The shape of a molecule
What is the shape of a molecule determined by??
By its bond angles
What does VSEPR theory stand for?
Valence Shell Electron Pair Repulsion
“The best arrangement of a given number of electron is the one that __________ repulsions among them”
Minimizes
Electron pairs, bonding and nonbonding, _____ each other.
Repel
Electrons pairs can be referred as
Electron domains
Predicted bond angle for 2 electron domains.(linear)
180
Predicted bond length for 3 electron domain.( trigonal planar)
120
Predicted bond length for 4 electron domains.( tetrahedral)
109.5
Predicted bond length for 5 electron domains. ( trigonal bypiramidal)
120, 90
Predicted bond length for 6 electron domains.( octahedral)
90
Molecular geometries that are possible for Trigonal planar:
- trigonal planar
- bent
Molecular geometries that are possible for Tetrahedral:
- tetrahedral
- Trigonal pyramidal
- bent
Molecular geometries that are possible for Trigonal bypiramidal.
- trigonal pyramidal
- seesaw
- T-shaped
- linear
Molecular geometries that are possible for Octahedral:
- octahedral
- square pyramidal
- square planar
what does the Heisenberg uncertainty principle state?
The position and the momentum of an electron can never be simultaneously, exactly known.
