Unit 2 Periodic Table, Chemical Formulas, Nomenclature, Simple Reactions, Balancing Reactions.

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Unit 2Periodic Table, Chemical Formulas, Nomenclature, Simple Reactions, Balancing Reactions

Periodic Table

Nomenclature: Molecular Compounds

Most are named by rules of Organic Chemistry

Simple Molecular compounds tend to be Binary nonmetallic

Use standard prefixes

2 kinds of elements

On the Right side of the periodic table

→ →

Nomenclature: Ionic Compounds

(–) ion(+) ion

Nomenclature: Simple Ions

Find patterns on the periodic table:

–2+2+

1 –3

Polyatomic ions may be involved… Let’s look at those…

A list appears in the appendix of your lab manual.

Nomenclature: Polyatomic Ions

Per ate - +1 oxygen ate - Most common ite - –1 oxygenHypo ite - –2 oxygens

ClO3–1

FO3–1

BrO3–1

IO3–1

ClO4–1

FO4–1

BrO4–1

IO4–1

ClO2–1

FO2–1

BrO2–1

IO2–1

ClO–1

FO–1

BrO–1

IO–1

Se–2

Te–2

SO4–2

SeO4–

TeO4–

The -ates

As–3

PO4–3

NO3–1

AsO4–

The -ates

Si–4

SiO3–2

CO3–2The -ates

Yikes!

BO3–3The -ates

On occasion, ionic compounds may exist as a hydrate.

A hydrate is when one or more water molecules (H2O) connect to a solid ionic compound.

Barium hydroxide octahydrate –

ZnCl2•6 H2O –

Ba(OH)2 • 8 H2OZinc chloride hexahydrate

Ionic compounds with transition metal ions – those that have multiple valences.

Nomenclature: Transition Metal Ions

This area!

+1+2+3+4 +5 +1+2+3+4

+5+1+2+3+4

+1+2+3+4 +5+6

Notice the patternsLeft to right

AndRight to left

+1+2+3+4 +5 +1+2+3+4

+5+1+2+3+4

+1+2+3+4 +5+6

+3+3+3 +3+3+3

What goes here?

+1+2+3 +1+2+3+4

+5+1+2+3+4

+1+2+3+4 +5+6

+3+3+3 +3+3+3+3+2

+1+2+3 +1+2+3+4

+1+2+3

+1+2+3 +2+3+4

+1+2+3

+2 +3 +6

mercury(I) = Hg2

mercury(II) = Hg+2

Stock system – Use a Roman numeral for the ionic charge (valence)

Traditional system – Use the Latin roots with –ic or –ous endings.

mercur-

cobalt-

stann-

plumb-

Traditional system – –ic ending

Considered the most common charge of the ions

–ous endingConsidered the second most common charge of the ions

Based on the trends shown on the periodic table, the most common charge is the highest charge listed; the second most common charges is the lower charge listed.

Nomenclature: Acid Compounds

Binary AcidsContain only hydrogen (H+) and one other element – a nonmetal

These are named with ‘hydro’ ‘ic acid’

Nomenclature: Acid Compounds

Ternary Acids (oxyacids)– Contain hydrogen and a polyatomic ion (a

oxyradical) that either ends in –ate or –ite.• -ate goes to –ic• -ite goes to –ous• Ponder gum… “If you ate it it is icky; but if

you bite it, it is delicious.”

Nomenclature: Practice

1. Decide which of the following are expected to be ionic and which are expected to be molecular:a) KF

b) N2O5

c) SiCl4

2. What is the formula of magnesium nitride?

3. What is the formula of calcium phosphate?

ioniccovalentcovalent

Ca3(PO4)2

4. Give the formula of carbon disulfide.

5. Give the formula of dinitrogen tetrafluoride.

6. Calcium chloride hexahydrate is used to melt snow from roads. What is the formula of this compound?

CaCl2•6 H2O

7. Name BaO.

8. Name Cr2(SO4)3.

9. Name OF2.

10.Name S4N4.

11.Bromine has an oxyacid HBrO2, whose name is bromous acid. What is the name and formula for the corresponding ion?

chromium(III) sulfate

barium oxide

oxygen difluoride

tetrasulfur tetranitride

BrO2–1 = bromite

12.Name HIO.

13.Name H3PO4.

14.A compound whose common name is green vitriol has the chemical formula FeSO4•7 H2O. What is the chemical name of this compound?

hypoiodous acid

phosphoric acid

iron(II) sulfate heptahydrate

General Reactions

• Synthesis– Two elements makes a Binary compound

• Fe + O2 Fe2O3

– Two oxides makes a Ternary compound• Metal oxide + water makes metal hydroxide

– BaO + H2O Ba(OH)2

• Nonmetal oxide + water makes acid

– N2O5 + H2O HNO3

• Metal oxide + Nonmetal oxide makes ternary compound

– BaO + N2O5 Ba(NO3)2

General Reactions

• Notice the ions are staying the same!!!– Oxygen is O–2

– Barium is Ba+2

– Hydroxide is OH–1

– Nitrate is NO3–1 and familiar

General Reactions

• Decomposition (the opposite of synthesis)– Binary compound will make two elements– Metal hydroxide makes metal oxide and water– Ternary acid makes nonmetal oxide and water– Ternary compound (many) makes nonmetal oxide

and metal oxide.• One of the most common is that of a metal

carbonate:

• MgCO3 MgO + CO2

– Metal chlorate makes metal chloride and oxygen gas

• Ba(ClO3)2 BaCl2 + O2

General Reactions

• Single Replacement– A metallic element + a compound switches

the positive ions.

• MgCO3 + Li Li2CO3 + Mg

– A nonmetallic element (usually a halogen) + a compound switches the negative ions.

• Cl2 + FeBr3 FeCl3 + Br2

General Reactions

• Double Replacement– Positive ions and Negative ions switch

positions.– Take time to identify these ions.

• MgCO3 + Sn(ClO3)4

Mg+2 CO3–2 Sn+4 ClO3

Sn(CO3)2 Mg(ClO3)2+

General Reactions

• Double Replacement– Try another

• Sb(OH)3 + Zn3P2→

Sb+3 OH–1 Zn+2 P–3

SbP + Zn(OH)2

General Reactions

• Combustion– Typically a hydrocarbon burns in the

presence of oxygen to create water and carbon dioxide• Hydrocarbons are made of –• On occasion, they include oxygen, as

well. • CH4 + O2

• C2H5OH + O2

→ CO2 + H2O

hydrogen + carbon

→ CO2 + H2O

General Reactions

• Acid-Carbonate– There must be an acid and a metal

carbonate – check for these BEFORE presuming double replacement.

– These will create water, carbon dioxide, and an ionic salt.• Li2CO3 + HNO2→ CO2 + H2O

Li+1 CO3–2 H+1 NO2

+ LiNO2

Balancing Reactions• Based on the Law of Conservation, is present

must be preserved. In other words, whatever happens to the reactants must occur to the products.– Choose a chemical – insert a coefficient

(multiplier) in front of it. Never change the subscripts!

– Treat ions (radicals) that appear on both sides as single chunks.

– ½’s can be used for diatomic elements.– It is helpful to think of water as HOH, rather

than H2O.

Balancing Reactions• Whatever happens to the reactants must occur to the

products.• Choose a chemical – insert a coefficient (multiplier) in

front of it. Never change the subscripts!• Treat ions (radicals) that appear on both sides as single

chunks.• ½’s can be used for diatomic elements.• It is helpful to think of water as HOH, rather than H2O.

MgCO3 + Sn(ClO3)4 Mg(ClO3)2 + Sn(CO3)2

→ 2 1 2 1

Balancing Reactions• Whatever happens to the reactants must occur to the

products.• Choose a chemical – insert a coefficient (multiplier) in

front of it. Never change the subscripts!• Treat ions (radicals) that appear on both sides as single

chunks.• ½’s can be used for diatomic elements.• It is helpful to think of water as HOH, rather than H2O.

C4H8OH + O2 CO2 + H2O→ 1 23/2

8 ? 2 9

4 C4H8OH + 23 O2 16 CO2 + 18 H2O

Unit 2 Periodic Table, Chemical Formulas, Nomenclature, Simple Reactions, Balancing Reactions.

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