Module 2

Question 1

Covalent compounds

Answer 1

Share electrons, usually have low boiling/melting points

Question 2

Non-polar covalent bonds

Answer 2

Electrons are shared equally

Question 3

Polar covalent bonds

Answer 3

Electrons are shared unequally, gives rise to dipole moments

Question 4

Dipole moment

Answer 4

Occurs when there’s a separation of charges within a bond, arises from differences in electronegativity

Question 5

How are bond order and length related?

Answer 5

Inversely. When bond order increases (triple bond vs single bond), bond length decreases

Question 6

How are bond length and bond energy related?

Answer 6

Inversely. As bond length decreases, bond energy increases.

Question 7

How are bond order and bond energy related?

Answer 7

Proportionally. As bond length increases, bond energy also increases

Question 8

Electron affinity

Answer 8

The amount of energy released when an electron attaches to a neutral form atom or molecule, while in a gaseous state. A physical quality, measures the attraction between the incoming electron and the nucleus

Question 9

Electronegativity

Answer 9

Describes how tightly an atom attracts electrons in a bond. It’s a dimensionless adjective, a quantity that is calculated, not measured.

Question 10

How to calculate formal charge

Answer 10

of valence electrons - # of lone pair electrons - 1/2 of the total number of bonding electrons

The 1/2 bonding electrons is equal to the number of bond lines drawn on the lewis structure attached to the atom in questions

To double check calculations, the sum of the formal charges for all the atoms in a molecule should be zero or equal to the charge of the ion if applicable

Question 11

Definition of formal charge

Answer 11

The hypothetical charge an atom would have if we could redistribute the electrons in the bonds evenly between the atoms. It’s not actually the charge of the atom in the molecule, it’s just a bookkeeping total

Question 12

Definition of solubility

Answer 12

The quantitative extent to which a substance may be dissolved in water

Question 13

When will a substance precipitate?

Answer 13

When its concentration in a given solution exceeds the substance’s solubility

Question 14

What is an oxyacid?

Answer 14

An acid molecule containing hydrogen, oxygen and one other element (usually a nonmetal)

Question 15

Definition of a solution

Answer 15

A homogenous mixture consisting of a solute and a solvent

Question 16

Definition of a solute

Answer 16

The substance in a solution that dissolves

Question 17

Definition of a solvent

Answer 17

The substance into which things are dissolved in a solution

Question 18

Concentration

Answer 18

The amount of solute per amount of solvent

Question 19

What are electrolytes?

Answer 19

Molecules that dissolve their charges into water and conduct electricity. Any and all acidic and basic molecules are electrolytes

Question 20

What makes something a non-elecrolyte?

Answer 20

Not being able to ionize in solution, therefore not conducting electricity. Includes polar covalent non-ionizing molecules, sugars, ethanol, organics, etc..

Question 21

Arrhenius acid

Answer 21

Generates H+ in aqueous solutions

Question 22

Arrhenius bases

Answer 22

Generates OH- in aqueous solutions

Question 23

Bronstead-Lowry acids

Answer 23

Molecule is a H+ donor

Question 24

Bronstead-Lowry bases

Answer 24

Molecule is an H+ acceptor

Question 25

What drives redox reactions?

Answer 25

Reduction in potential energy

Question 26

How do you recognize an acid/base reaction?

Answer 26

Water and a salt are formed from an acid and a base

Question 27

Criteria for an ideal gas

Answer 27

Infinitely small volume and perfectly elastic collisions

Question 28

List of memorized strong acids

Answer 28

HCl, HBr, HI, H2SO4, HClO4, HNO3

Question 29

Strong bases

Answer 29

All alkali metal hydroxides (NaOH, KOH, etc) and alkaline earth metal hydroxides (Mg(OH)2, etc)

Question 30

2 ligands, 2 electron groups

Answer 30

Linear

Question 31

2 ligands, 3 electron groups

Answer 31

Bent

Question 32

2 ligands, 4 electron groups

Answer 32

Bent

Question 33

3 ligands, 3 electron groups

Answer 33

Trigonal planar

Question 34

3 ligands, 4 electron groups

Answer 34

Trigonal pyramidal

Question 35

4 ligands, 4 electron groups

Answer 35

tetrahedral

Question 36

Which bond angle is greater: the ones between the ligands of a trigonal pyramidal molecule, or the ones between the ligands of a tetrahedral ligand?

Answer 36

Tetrahedral is 109.5 Trigonal planar is <109.5

Question 37

Bond angles between the ligands of a tetrahedral molecule

Answer 37

109.5

Question 38

Bond angles between the ligands of a trigonal pyramidal molecule

Answer 38

< 109.5

Question 39

Bond angles between the ligands of a trigonal planar molecule

Answer 39

120

Question 40

Bond angles between the ligands of a linear molecule

Answer 40

180

Question 41

Bond angles between the ligands of a bent molecule (linear with a bonus electron group)

Answer 41

< 180

Question 42

Bond angles between the ligands of an extra ment molecule (linear with two bonus electron groups)

Answer 42

<< 180

Question 43

Steps to balancing redox rxns

Answer 43

1. Split into half rxns 2. Balance everything that's not O or H 3. Add water to balance O 4. Add H+ to balance H 5. Add electrons to balance charge 6. Combine 7. Add one hydroxide for every H+ on both sides 8. Combine H+ with OH- to form water 9. Cancel anything remaining and combine