Unit 3: Compounds

Question 1

how to draw lewis structure

Answer 1

1) Count all valence electrons
2) Determine the central atom (element that is fewest in number)
3) Draw single bonds between the different atoms in the molecule
4) Put all remaining electrons in as bonds or lone pairs, and try to give each atom an octet

Question 2

electron donor/ acceptor

Answer 2

An electron acceptor is a chemical entity that accepts electrons transferred to it from another compound. … In chemistry, a class of electron acceptors that acquire not just one, but a set of two paired electrons that form a covalent bond with an electron donor molecule, is known as a Lewis acid.

Question 3

if you have 4 nonboding pairs plus bonds, and 4 bonds plus nonbinding pairs, whats the geometry and arrangement

Answer 3

Geometry: tetrahedral

Arrangement: tetrahedral

Question 4

if you have a total of 3 nonbinding pairs plus bonds and 3 bonds plus nonbonding pairs, whats the geometry and arrangement?

Answer 4

Geometry: Trigonal Planar

Arrangement: Trigonal Planar

Question 5

monoatomic ion

Answer 5

A monatomic ion is an ion consisting of a single atom. If an ion contains more than one atom, even if theseatoms are of the same element, it is called a polyatomic ion. For example, calcium carbonate consists of the monatomic ion Ca2+ and the polyatomic ion CO32−.

Question 6

What are all compounds made of

Answer 6

All compounds are made of more than one element bonded together

Question 7

resonance

Answer 7

When there is more than one good Lewis structure, we draw ALL Lewis structures and put double headed arrows between them. These are called resonance structures. The weighted average tells us about the actual structure.

The actual structure of a molecule is NOT switching back and forth between different resonance forms. Rather the actual structure is the average of the different resonance forms. All of the electrons in molecules move extremely fast.

Question 8

non-electrolyte

Answer 8

a substance that does not readily ionize when dissolved or melted and is a poor conductor of electricity.

Question 9

pauling electronegativity

Answer 9

derived from bond strength. A–B bond is STRONGER than the average of A–A and B–B! Difference is assumed to be “ionic” in nature

Question 10

if you have a total of 3 nonbinding pairs, but a total of 2 bonds plus 1 nonbonding pair whats the geometry and arrangement?

Answer 10

Geometry: trigonal planar

Arrangement: bent

Question 11

if you have 4 nonbinding and bonds total, but 1 bond and 3 nonbinding pairs, whats the geometry and arrangement

Answer 11

Geometry: tetrahedral

Arrangement: linear

Question 12

electrolyte

Answer 12

An electrolyte is a substance that will dissociate into ions in a solution. The ions in the solution give it the capacity to conduct electricity.

Question 13

just look at the picture

Question 14

in a covalent what are the electrons shared between both atoms considered to be?

Answer 14

The shared electrons are considered as owned by BOTH atoms! (Both hydrogens now have 2 electrons.)

Question 15

electronegativity

Answer 15

Electronegativity is the ability of an atom to pull electrons towards itself.

Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The Pauling scale is the most commonly used.

A measure of how much an atom wants electrons.

Question 16

if you have a toatl for 4 nonbinding pairs and bonds, but 2 are bonds and 2 are nonbinding, whats the geometry and arrangement

Answer 16

Geometry: Tetrahedral

Arrangement: bent

Question 17

whats all the possible arrangements of electron domains if you have 2 nonbonding pairs plus bonds

Answer 17

Nobonding Pairs Plus Bonds:

Number of Bonds plus Nonbinding Pairs: 2

Geometry of Nonbinding Pairs and Bonds bout the Central Atom: linear

Arrangement of the Atoms of the about the central atom: linear

Question 18

electrostatic force

Answer 18

Coulomb force, also called electrostatic force or Coulomb interaction, attraction or repulsion of particles or objects because of their electric charge.

Question 19

VSPER?

Answer 19

Valence shell electron pair repulsion (VSEPR) theory is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gillespie-Nyholm theory after its two main developers.

Question 20

polyatomic atoms

Answer 20

A polyatomic ion, also known as a molecular ion, is a charged chemical species (ion) composed of two or more atoms covalently bonded or of a metal complex that can be considered to be acting as a single unit. The prefix poly- means “many,” in Greek, but even ions of two atoms are commonly referred to as polyatomic.

Question 21

chemical bond

Answer 21

Chemical bond referrs to the forces holding atoms together to form molecules and solids. This force is of electric nature, and the attraction between electrons of one atom to the nucleus of another atom contribute to what is known as chemical bonds. A chemical bond formed between two ions with opposite charges

Question 22

disassociation

Answer 22

Dissociation in chemistry and biochemistry is a general process in which molecules (or ionic compounds such as salts, or complexes) separate or split into smaller particles such as atoms, ions or radicals, usually in a reversible manner.

Question 23

expanded octet

Answer 23

“Expanded octet” refers to the Lewis structures where the central atom ends up with more than an octet, such as in PCl5 or XeF4. In drawing the Lewis structure for PCl5 , there is a total of 40 valence electrons to put in (5 + 5x7 = 40).

Question 24

Covalent bond

Answer 24

A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.

Question 25

dipole

Answer 25

The polarity of a molecule is measured by its dipole moment. The larger the dipole moment, the stronger the charge separation.

The dipole moment of H2O is 1.85 D, which means water is VERY polar. Large dipole moments are a result of large differences in electronegativity.

Question 26

formal charge

Answer 26

•How to Assign Formal Charges

–For each atom, count the electrons in lone pairs and half the electrons it shares with other atoms.

–Subtract that from the number of valence electrons for that atom: the difference is its formal charge.

Question 27

list all characteristics of Ionic Compounds

Answer 27

HIGH melting/boiling points metal (or NH4+) & non-metal conduct electricity atoms gain/lose electrons positive ion = cation negative ion = anion

Question 28

non-polar covalent bond

Answer 28

Image result for nonpolar covalent bond definition Nonpolar covalent bonds are a type of chemical bond where two atoms share a pair of electrons with each other

Question 29

crystal lattice

Answer 29

the symmetrical three-dimensional arrangement of atoms inside a crystal.

Crystals are composed of three-dimensional patterns. These patterns consist of atoms or groups of atoms in ordered and symmetrical arrangements which are repeated at regular intervals keeping the same orientation to one another. By replacing each group of atoms by a representative point a crystal lattice is obtained.

Question 30

octet rule

Answer 30

Atoms with 1, 2, or 3 valence electrons will usually lose them all to become cations.

Atoms with 5, 6, or 7 valence electrons will usually gain electrons in order to give it eight valence electrons.

Question 31

polar covalent bond

Answer 31

Polar covalent bonding is a type of chemical bond where a pair of electrons is unequally shared between two atoms. In a polar covalent bond, the electrons are not equally shared because one atom spends more time with the electrons than the other atom.

Question 32

list all characteristics of covalent compounds

Answer 32

low melting/boiling points only non-metals (except TiCl4) don’t conduct electricity (except acids and bases) atoms share electrons

Question 33

Allen EN

Answer 33

Average energy of all the valence electrons. (Can be measured for all elements)

Question 34

if you have a total of 4 nonbinding pairs plus bonds but 3 bonds and 1 nonbinding and 3 binding, whats the geometry and arrangement

Answer 34

Geometry” tetrahedral

Arrangement: trigonal pyramidal