Chem chap 2-3

Question 1

How are covalent bonds formed?

Answer 1

They are bonds that are formed between two non-metals when they share their valence electrons.

Question 2

How are ionic bonds formed?

Answer 2

They are bonds that are formed between a metal and non-metal when the metal gives away electrons to a non-metal.

Question 3

What are the two types of compounds?

Answer 3

Ionic and Molecular Compounds.

Question 4

What are the observable properties of ionic compounds?

Answer 4

Type of Bond - Ionic
Involves - Cation + Anion
Within the bond, electrons are transfering (M → NM).
Forces between compounds are strong.
Boiling/melting points are usually high.
Usual state at room temperature - Solid
Arrangement - Regular repeating array of cations and anions (“crystal lattice”)
Soluble? - Yes
Electrolyte? - Yes
Are there any prefixes for basic naming? - No
Chemical formula subscripts can be predicted by crossing charges.

Question 5

What are the observable properties of molecular compounds?

Answer 5

Type of Bond - Covalent
Involves non-metals only.
Within the bond, electrons are shared.
Forces between compounds are weak.
Boiling/melting points are usually low.
Usual state at room temperature - Liquid/Gas
Arrangement - Individual molecules
Soluble? - usually no
Electrolyte? - usually no (except acids)
Are there any prefixes for basic naming? - Yes
Chemical formula cannot be predicted, it must be provided.

Question 6

Draw the NaCl lewis diagram.

Answer 6

Please draw.

Question 7

Draw the PCl5 lewis diagram.

Answer 7

Please draw.

Question 8

Define electronegativity.

Answer 8

Electronegativity is a property that describes an atom’s ability to attract electrons.

Question 9

Define non-polar covalent.

Answer 9

Bonded atoms that have no or little difference in electronegativity.

Question 10

Define polar covalent.

Answer 10

Atoms that have significant differences (ΔEN > 0.5).

Question 11

Is OCl2 a polar bond?

Answer 11

Yes

Question 12

Is H2S a polar bond?

Answer 12

No

Question 13

Is CH3Cl a polar bond?

Answer 13

Yes

Question 14

Define polar molecule.

Answer 14

Polar molecules are entire molecules that have partially positive and negative ends.

Question 15

What is the difference between a polar molecule and a polar bond.

Answer 15

A polar bond is one where the charge distribution between the two atoms in the bond is unequal. A polar molecule is one where the charge distribution around the molecule is not symmetric.

Question 16

Is BeCl2 a polar bond or a polar molecule?

Answer 16

Polar bond.

Question 17

Is H2S a polar bond or a polar molecule?

Answer 17

Neither.

Question 18

Define intermolecular force (IMF).

Answer 18

Forces of attraction between molecules.

Question 19

What is dipole-dipole force?

Answer 19

Attraction between polar molecules.

Question 20

What are hydrogen “bonds” (H-bonds)?

Answer 20

Occurs in molecules where H is bonded to highly electrongative atoms.

nitrogen (N)
oxygen (O)
fluorine (F)

Question 21

What is London dispersion force?

Answer 21

Weak attractive force experienced by ALL molecules.

Question 22

Which IMFs does H2S have?

Answer 22

London Dispersion Force

Question 23

Which IMFs does SO2 have?

Answer 23

London Dispersion Force, Dipole-Dipole Force

Question 24

Which IMFs does CH3OH have?

Answer 24

London Dispersion Force, Dipole-Dipole Force, H-bond

Question 25

The more _____ the Dipole-Dipole Forces in the molecule, the ________ the forces that exist between them.

Answer 25

polar, stronger

Question 26

H-bonds are ________ than a regular dipole-dipole.

Answer 26

stronger

Question 27

The ______ the LDF molecule, the more _________ it has.

Answer 27

larger, electrons

Question 28

IMPORTANT THINGY TO MEMORIZE.

Answer 28

more electrons = larger number of LDF 🡪 stronger forces

more electrons = larger electron cloud 🡪 more polarizable 🡪 stronger forces