General Chemistry Ch 3. Bonding and Chemical Interactions

Question 1

Chemical bonding general

Answer 1

Formed via the interaction of the valence electrons of the combining atoms, can be ionic or covalent, elements typically form bonds to attain a noble gas like electron configuration

Question 2

Octet rule

Answer 2

Elements will be the most stable with eight valence electrons, some exceptions including incomplete octets, expanded octet, and odd number of electrons

Question 3

Ionic bond

Answer 3

Formed by the transfer of one or more electrons from an element with relatively low ionization energy to an element with a relatively high electron affinity, occurs between elements with large differences in electronegativity (usually a metal and non metal), electrostatic attraction between ions causes them to remain in close proximity, electrons not shared, stronger than covalent bonds

Question 4

Cation

Answer 4

Positively charged ion, loses electrons from neutral to become cation

Question 5

Anion

Answer 5

Negatively charged ion, gains electrons from neutral to become anion

Question 6

Crystalline lattices

Answer 6

Large, organized arrays of ion formed by ionic compounds, repeating rows of cations and anions, maximizes forces between oppositely charged ions and minimizes forces between the same ions

Question 7

Ionic compounds

Answer 7

Unique physical and chemical properties, tend to dissociate in water and other polar solvents, tend to have high melting points, when in molten or aqueous states are good conductors of electricity

Question 8

Covalent bond

Answer 8

Formed by the sharing of electrons between two elements of similar electronegativities (usually nonmetals), characterized as nonpolar or polar, weaker than ionic bonds

Question 9

Bond order

Answer 9

The number of shared electron pairs between two atoms, determines whether a covalent bond is a single bond, double bond, or triple bond, as bond order increases bond strength increases, bond energy increases, and bond length decreases

Question 10

Bond strength

Answer 10

Increases with bond order

Question 11

Bond energy

Answer 11

Increases with bond order, the energy required to break a bond by separating its components into their isolated, gaseous atomic states

Question 12

Bond length

Answer 12

Decreases with bond order, the average distance between the two nuclei of atoms in a bond

Question 13

Nonpolar bonds

Answer 13

Resulting molecules in which both atoms have exactly the same electronegativity, some bonds are considered non-polar when there’s a very small difference in electronegativity

Question 14

Polar bonds

Answer 14

Form when there is a significant difference in electronegativity’s but not enough to transfer electrons and form ionic bonds, electrons shared unevenly, the more electronegative element takes on a partial negative charge, and the less electronegative element takes on a partial positive charge, creates a dipole

Question 15

Coordinate covalent bonds

Answer 15

Result when a single atom provides both bonding electrons while the other atom does not contribute any, coordinate covalent bonds are most often found in Lewis acid base chemistry

Question 16

Lewis dot symbols

Answer 16

Chemical representation of an atoms valance electrons

Question 17

Formal charges

Answer 17

Exist when an atom is surrounded by more if you were valance electrons and it has and it’s neutral state (assuming equal sharing of electrons in a bond)

Question 18

Resonance structures

Answer 18

Represent all of the possible configurations of electrons, stable and unstable, that contribute to the overall structure, exist for any molecule with a pi system of electrons

Question 19

Valance shell electron pair repulsion (VSEPR) theory

Answer 19

Predicts the three-dimensional molecular geometry of covalently bonded molecules, electrons in this theory, whether bonding or non-bonding, arrange themselves to be as far apart as possible from each other in three-dimensional space leading to geometric cute trees

Question 20

Non bonding electrons VSEPR

Answer 20

Exert more repulsion than bonding electrons because they reside closer to the nucleus

Question 21

Electronic geometry

Answer 21

Refers to the position of all electrons in a molecule

Question 22

Molecular geometry

Answer 22

Refers to the position of only the bonding pairs of electrons in a molecule

Question 23

Polarity of molecules

Answer 23

Is dependent on the diaper moment of each bond and the sum of the dipole moment in the molecular structure, polar molecules contain polar bonds, nonpolar molecules may contain nonpolar bonds or polar bonds that cancel each other out

Question 24

Sigma bonds

Answer 24

The result of head to head overlap

Question 25

Pi bonds

Answer 25

The result of the overlap of two parallel electron cloud densities

Question 26

Intermolecular forces

Answer 26

Electrostatic attraction between molecules, they are significantly weaker than covalent bonds

Question 27

London dispersion forces

Answer 27

The weakest interactions, but are still present in all atoms and molecules, as the size of the atom or structure increases so does the corresponding London dispersion force

Question 28

Dipole dipole interactions

Answer 28

Occur between oppositely charged ends of polar molecules, are stronger than London forces, these interactions are evident in the solid and liquid phases but negligible in the gas phase due to the distance between particles

Question 29

Hydrogen bonds

Answer 29

Specialized subset of dipole dipole interactions involved an intra-and intermolecular attraction, hydrogen bonding occurs when hydrogen is bonded to one of the three very elect electronegative atoms: fluorine, oxygen, nitrogen

Question 30

Incomplete octet

Answer 30

Elements that do not follow octet rule because they are stable with fewer than 8 electrons in their valence shell and include H, He, Li, Be, and B

Question 31

Expanded octet

Answer 31

Elements that do not follow octet rule because they can hold more than 8 electrons by incorporating d orbitals, includes any element in period 3 or greater

Question 32

Odd numbers of electrons

Answer 32

Molecules that cannot follow octet rule because they cannot distribute electrons in a way where all atoms involved have 8 valence electrons

Question 33

Covalent compounds

Answer 33

Tend to have lower melting and boiling points, do not break down into constituent ions, are poor conductors of electricity in liquid or aqueous states

Question 34

Partial negative charge

Answer 34

Characteristic of the more electronegative element in a polar covalent bond

Question 35

Partial positive charge

Answer 35

Characteristic of the less electronegative element in a polar covalent bond

Question 36

Dipole moment equation

Answer 36

p = q*d

p - the dipole moment
q - the magnitude of the charge
d - the displacement vector separating the two partial charges

Question 37

Bonding electrons

Answer 37

Electrons involved in a covalent bond in the valance shell