APCHEM Written final review

Question 0

5 basic VSEPR Shapes & angles

Answer 0

Linear-Linear 180
Trigonal planar(trigonal planar, bent) 120
Tetrahedral (tetrahedral, trigonal pyramidal, bent) 109.5
Trigonal bipyramidal (trigonal bipyramidal, seesaw t-shaped, linear) 120&90
Octahedral (octahedral, square pyramidal, square planar) 90

Question 1

VSEPR

Answer 1

Valence shell electron pair repulsion theory- both bonding and nonbonding elections in the valence shell of an element repel each other and seek to be as far apart as possible (basically the electrons are going to spread out as far as possible to minimize interactions with other electrons)

Question 2

Polarity rules

Answer 2

No lone pairs of electrons or all same atoms= Nonpolar and symmetrical

Question 3

Describe atomic radius trends

Answer 3

Atoms get large as you move down a group and atoms get smaller as you move from left to right across the period

Question 4

Describe the trend for ionic radius

Answer 4

Cations will be smaller than their parent atoms, because when electrons are lost by an atom, sometime it empties its outermost shell, or simply losing electrons decreases electron electron repulsion

Anions are larger than their parent atoms because there is an increase in electron electron repulsion

Question 5

What is ionization energy?

Answer 5

the energy needed to remove an electron from an atom
(Higher=holds on tightly aka smaller atoms)
(Lower=holds on loosely aka larger atoms)

Question 6

Ionization energy trends

Answer 6

Ionization energy increases as you move to the right, because the atoms are getting smaller and the electrons are thus closer to the nucleus and held tighter.
Ionization energy decreases as you move down a group, because atoms get larger and the elctrons are further from the nucleus and easier to remove.

Question 7

What is electron affinity?

Answer 7

Energy change that occurs when an atom gains an electron

The more negative the EA value, the more atoms want electrons and the higher the EA is

Question 8

Electron affinity trends

Answer 8

Noble gases always have the lowest EA
Metal vs Nonmetal- Nonmetal has a higher EA because it wants to gain electrons and become stable
Nonmetal vs Nonmetal- The one closest to the noble gas, or if they are tied, the smaller one

Question 9

Units for C?

Answer 9

J/gK