week 1

Question 1

define chemistry

Answer 1

the study of nature, properties and transformations of matter

Question 2

define matter

Answer 2

anything that has mass and occupies space

Question 3

what governs bonding?

Answer 3

electronic structure

Question 4

what governs molecular structure and reactivity?

Answer 4

bonding

Question 5

rule for shell capacity

Answer 5

2n^2 (n = shell number)

Question 6

s orbital spheres ______ in size as you travel down a group

Answer 6

increase

Question 7

groups have …

Answer 7

similar chemical properties

Question 8

covalent bonds …

Answer 8

share electrons

Question 9

ionic bonds…

Answer 9

transfer electrons

Question 10

nonmetals are more likely to…

Answer 10

keep electrons

Question 11

metals are more likely to…

Answer 11

give away electrons

Question 12

nonpolar covalent bond electronegativity difference range

Answer 12

0.0 - 0.4

Question 13

polar covalent bond electronegativity difference range

Answer 13

0.4 - 2.0

Question 14

ionic bond electronegativity difference range

Answer 14

2.0 - 4.0

Question 15

relationship between covalent bonds and orbitals

Answer 15

a covalent bond forms when a portion of an atomic orbital of one atom overlaps a portion of an atomic orbital of another atom

Question 16

what is hybridization?

Answer 16

when an orbital overlaps another orbital, fusing together

eg. s and p^3 become sp^3

Question 17

how is the lewis structure drawn?

Answer 17

without orbitals

Question 18

nonbonding electrons are assigned where?

Answer 18

to the atom on which they are located

Question 19

bonding electrons are assigned where?

Answer 19

divided equally between bonded atoms

Question 20

formal charge equation

Answer 20

formal charge = valence e - nonbonding e - (bonding e/2)

Question 21

resonance is?

Answer 21

electron pair delocalisation (spread over entire molecule)

Question 22

2 electron domains form what shape?

Answer 22

linear (180 degrees)

Question 23

3 electron domains form what shape?

Answer 23

trigonal planar (120 degrees)

Question 24

4 electron domains form what shape?

Answer 24

tetrahedral (109.5 degrees)

Question 25

5 electron domains form what shape?

Answer 25

trigonal bipyramidal (120 and 90 degrees)

Question 26

6 electron domains form what shape?

Answer 26

octahedral (90 degrees)

Question 27

VSEPR stands for?

Answer 27

valence shell electron pair repulsion

Question 28

symmetrical molecules are...

Answer 28

nonpolar

Question 29

non-symmetrical molecules are...

Answer 29

polar

Question 30

K (at equilibrium) equation

Answer 30

[Beq]/[Aeq]

Question 31

K much < 0.001

Answer 31

only reactants at equilibrium, basically no reaction occurs

Question 32

0.001 < K < 1

Answer 32

more reactants than products at equilibrium

Question 33

1 < K < 1000

Answer 33

more products than reactants at equilibrium

Question 34

K much > 1000

Answer 34

only products at equilibrium, reaction goes until completion

Question 35

le chatelier's principle

Answer 35

when a stress is applied to a system at equilibrium, the equilibrium shifts to relieve the stress and to restore a equilibrium

Question 36

lewis acid vs bronsted-lowry environment

Answer 36

lewis acid works in any environment whereas bronsted-lowry implies the presence of water

Question 37

an acid is a...

Answer 37

proton donor

Question 38

a base is...

Answer 38

a proton acceptor

Question 39

formula for calculating pH

Answer 39

-log10[H3O+]

Question 40

formula for calculating pOH

Answer 40

-log10[OH]

Question 41

Kw equation

Answer 41

[H3O+] x [OH-] = 1 x 10^-14 at 25 degrees = Kw

Question 42

pKa equation

Answer 42

-log10(Ka)

Question 43

pKb equation

Answer 43

-log10(Kb)

Question 44

what is Ka?

Answer 44

the acid dissociation constant

Question 45

when kA is large...

Answer 45

pKa is small (strong acid)

Question 46

define buffer

Answer 46

solutions that maintain the pH approximately constant despite small addition of acid or base, thus resisting changes in pH

Question 47

what is generally in buffers?

Answer 47

usually a mixture of a weak acid and its conjugate base

Question 48

equation to find pH using pKa

Answer 48

pH = pKa + log([A-]/[HA])

Question 49

how do buffers work?

Answer 49

when small amounts of H3O+ or OH- are added, they cause a small amount of one buffer component to convert into the other

Question 50

buffers only work when...

Answer 50

the solution is around the buffer region