Chapter 6

Question 1

bond length

Answer 1

distance b/w two nuclei

Question 2

bond type

Answer 2

single bond has bond order 1, double has bond order 2 and so on.

Question 3

bond enthalpy

Answer 3

energy. bond energy (enthalpy) increases as bond type increases

Question 4

covalent bonding

Answer 4

sharing of electrons, but not all electrons are shared equally. polar- (not shared equally, creates a charge) nonpolar- (electrons shared equally)

Question 5

ionic bonding

Answer 5

bonding occurring usually between a metal and nonmetal.

Question 6

electronegativity

Answer 6

ability of an atom to draw shared electrons towards itself. (determines how electron density is distributed)

Question 7

Fluorine electronegativity

Answer 7

4

Question 8

why does O have a higher electronegativity than Cl

Answer 8

the valence electrons on Cl are further away from the nucleus and feel less attraction to the nucleus, therefore lowering electronegativity.

Question 9

difference in EN less than 0.5

Answer 9

nonpolar covalent

Question 10

difference in EN less than 0.5

Answer 10

nonpolar covalent

Question 11

change in EN =0.5-2.0

Answer 11

polar covalent

Question 12

difference in EN greater than 2

Answer 12

ionic

Question 13

Drawing lewis structure tips

Answer 13

1. carbon atoms are always central atoms
2. hydrogen are always terminal atoms
3. central atoms usually have lowest electronegativity values

Question 14

Isoelectronic species

Answer 14

species with the same amount of paired and unpaired electrons

Question 15

formal charge

Answer 15

the charge distribution in a molecule. Assumes lone pairs belong to an individual atom and bonding pairs are shared equally.

FC= # electrons in neutral atom - [# of lone pair electrons + l/2 # bonding electrons]

Question 16

electroneutrality principle

Answer 16

formal charge should be 0 optimally, and any neg. charge should be on the most electronegative element.

Question 17

resonance

Answer 17

multiple valid lewis structures. Only multiple bonds have lewis structures. A molecule is never in one resonate structure at a time, and neither accurately represents the molecule. It is a hybrid.

Question 18

Exceptions to the Octet rule

Answer 18

1. central atom has fewer than 8 electrons due to shortage of electrons (group 13 elements)
2. central atom has fewer than 8 electrons due to odd numbered species
3. central atom has more than 8 electron (hypervalent, period 3 and higher p block)