Oxidation Numbers, Covalent Bonds, Ions

What is hydrogen's oxidation number in C₆H₁₂O₆?

+1

What is the oxidation number of hydrogen in HBrO?

+1

What must be the oxidation number of Br to make the overall charge of the molecule 0 in in HBrO?

+1

Oxidation state of H in H₂O is _____, but is _____ in NaH

+1, -1.

The oxidation number of hydrogen in a compound is ___, except when hydrogen forms compounds with active metals, in which case it is ___.

+1, -1.

What must tin's oxidation number be so that the overall charge of SnCl₃⁻ is -1

+2

What is the oxidation state of aluminum in Al(NO₃)₃?

+3

What must carbon's oxidation number to make the overall charge of in C₂O₄²⁻ be -2?

+3

What must the oxidation number of carbon in CO₂

+4

What must be the oxidation number of Nitrogen to make the overall charge of NO₃⁻¹ a -1?

+5

What is the oxidation number of chlorine in SnCl₃⁻?

-1

In the sulfate ion, (SO₄)⁻², what is do the oxidation numbers of the sulfur and the oxygens add up to?

-2

What is oxygen's oxidation number in C₆H₁₂O₆?

-2

What is oxygen's oxidation number in HBrO?

-2

What is the oxidation number of an oxygen atom in Al(NO₃)₃?

-2

What is the oxidation number of oxygen in CO₂?

-2

What is the oxidation number of oxygen in C₂O₄²⁻ ?

-2

In a sulfate ion, (SO₄)⁻², The oxygens have an oxidation state of ____ , and the sulfur is _____.

-2, +6

In H₂O, the oxygen has an oxidation state of ______, in H₂O₂, it is _____.

-2, -1

The oxidation number of oxygen in a compound is ___, except in peroxides when it is ___, and when combined with fluorine, in which case it is ___.

-2, -1, +2.

Special notes

-boron only needs 6 valence electrons to be full -use brackets and the charge when it is a polyatomic molecule

What is carbon's oxidation number in C₆H₁₂O₆?

0

What is the sum of the oxidation numbers in NaCl?

0

mono

1

VSEPR Shape determination

1. Geometry of the molecule is based on the electron pairs moving away from other electron pairs 2.The location and # of electron pairs around the central atom determine the shape 3. Minimizes the repulsion of shared and unshared pairs of electrons around the central atom

Steps for Lewis Structures

1. Write Formula 2. Find total # of valence electrons 3. Place 1st element listed in middle as the central atom (except hydrogen) and attach other atoms to it 4. Place lone pairs around each atom 5. If the central atom doesn't have a full octet then you use double or triple bonds.

Writing Covalent Bonds Rules

1.1st elements name does not change 2. 2nd element adds -ide to the ending 3. Prefixes included to indicate the number of atoms present for that element (first prefix not included when there is only 1 of that element)

deca

10

di

2

Linear

2 atoms, 0 lone pairs, 180 degrees

tri

3

Trigonal Planar

3 atoms , 0 lone pairs, 120 degrees

tetra

4

Trigonal Pyramidal

4 atoms , 1 lone pair, about 109 degrees

Tetrahedral

4 atoms attached , 0 lone pairs, 109 degrees

Bent

4 lonepairs/atoms 2 lone pairs, 104.5 degrees

penta

5

hexa

6

hepta

7

octa

8

nona

9

Define: Reduction

A decrease in oxidation number.

NH₃

Ammonia

Define: Oxidation

An increase in oxidation number.

Covalent Bonds

Bond forms when 2+ non metals share their valence electrons in order to fill their octet

Resonance Structure

Can be drawn for covalent compounds that have double and or triple bonds to indicate the movement of electrons in the compound

C₂H₆

Ethane

C₂H₄

Ethene

C₂H₂

Ethyne

HCN

Hydrocyanic acid

HF

Hydrofluoric acid

Why doesn't Hydrogen need a full octet?

It doesn't have a p orbital so it only needs two electrons

The oxidation number of a monatomic ion is equal to...

Its charge

CH₄

Methane

7 diatomic Molecules

N2,O2, F2, Cl2, Br2, I2, H2, (create a 7 with the -1 and carbon through fluorine)

What is the oxidation number of the two elements in NaCl:

Na has an oxidation number of +1 and Cl has an oxidation number of -1.

Expanded Octets

Occur for non metals in rows 4-7 where the central atoms can hold more than 8 electrons b/c the extra electrons expand/fill into the d-orbital

O₃

Ozone

Polarity Significance

Polar and non polar molecules do not mix, so when we explore solutions being able to identify polarity will be critical. polarity will allow one to determine if two compounds will mix in their liquid form

Non Polar Bond

Sharing the electrons equally, either in a bond or within the total compound (identical elements that made up the compound) (atoms are being pulled equally)

SiO₂

Silicon Dioxide/Quartz

Electronegativity

The ability of an atom in a compound to attract electrons to itself

The sum of the oxidation numbers in the formula for a polyatomic ion is equal to ___ ______ __ ____ ___.

The charge of that ion.

(PO₄)³⁻

phosphate

Ag+

silver

(SO₄)²⁻

sulfate

(SO₃)²⁻

sulfite

Fe3+

iron (III)

Pb2+

lead (II)

Pb3+

lead (III)

NO₃⁻

nitrate

NO₂⁻

nitrite

MnO₄⁻

permanganate

(O₂)²⁻

peroxide

Polar Bond

Unequal sharing of electrons within a compound (when lone pairs pull the atoms unequally)

VSEPR

Valence Shell Electron Pair repulsion

The oxidation number of an atom in the elemental state is...

Zero

The sum of the oxidation numbers in the formula of a compound is...

Zero

What is the oxidation number of Cl₂ and Al?

Zero

CH₃COO⁻

acetate

NH₄⁺

ammonium

H(CO₃)⁻

bicarbonate (hydrogen carbonate)

(CO₃)²⁻

carbonate

Cu+

copper (I)

Cu2+

copper (II)

CN⁻

cyanide

Molecule

formed when two or more atoms bond covalently

HCl

hydrochloric acid

OH⁻

hydroxide

Fe2+

iron (II)