WRITING & NAMING CHEMICAL COMPOUNDS

UNIT 4

• What is the Periodic Table?

• Periodic Trends

• Metals and Nonmetals

• What is the Oxidation number?

• More on Ionic Compounds

• Binary Naming of Ionic Compounds

• Polyatomic Ions

• Molecular Compounds

• Little bit of Organic Chemistry (Hydrocarbons)

• Diatomic's

PERIODIC TABLE

• Organization of elements in increasing atomic number/number of protons from left to right and from top to bottom

• The horizontal “rows” are called periods

• Vertical “rows” are called columns or families

• Three types of elements: Metals, Nonmetals, & Metaloids

METALS AND NONMETALS

• There are many more metals then nonmetals

• Metaloids make up the “Stairs”

METALS CHARACTERISTICS• Have luster (shiny)

• Can conduct electricity this is means that they are conductors

• Ductile- can be pulled out into a wire

• Malleable- can be hammered into thing sheets

• Always lose electrons from their Valance energy level to form positive Ions or Cations

• The Roman numeral or numbers with an “A” beside them at the top of the column on the periodic table are the number of electrons in the Valence electrons each element in the column has

NONMETALS

• Do not have luster and are frequently powdery, liquid or gaseous

• do not conduct electricity

• not ductile or malleable

• Always gains electrons in there Valance energy level until they have 8 of electrons (octet rule) and for negative ions which are called Anions

PERIODIC TABLE CONTINUED

• Each Family group has the same number of electrons and will either gain or lose electrons to have a fully filled valence shell (8 of Valance electrons), a halfway filled valence shell (4 of Valance electrons), or an empty valence shell (0 pairs of Valance electrons).

• Because of this, names were assigned to each family

FAMILY 1: ALKALI METALS

• These elements have 1 single valance electron

• These elements what to have an empty valance shell so they tend to loose their electron when binding to nonmetals

• These elements are the most reactive

• https://youtu.be/I8tOtZKpi04

FAMILY 2: ALKALINE EARTH METALS• These elements tend to lose 2 valance Electrons they

have an oxidation of +2 making them very reactive

FAMILY 17: HALOGENS

FAMILY 3-12: TRANSITION METALS

FAMILY18: NOBLE GASES

• 38 elements. The valence electrons are present in more then one shell this is why they have several oxidation states.

• Nonmetals with 7 valence electrons in its outer shell. Oxidation number of -1

• These elements have a full valence shell making them very nonreactive, oxidation number is 0

WHICH FAMILY BELONGS TO THE NONMETALS?

• Alkaline

• Alkaline Earth

• Transitions

• Hallogens

WHICH OF THESE ELEMENTS BELONG TO THE ALKALINE EARTH METALS?

• Li

• K

• Ca

• C

• Br

WHAT FAMILY DOES FLORINE BELONG TO? NOT MULTIPLE CHOICE

HALLOGENS

WHAT FAMILY (COLUMN) DOES THE NOBLE GASES MAKE UP? NOT MULTIPLE CHOICE

PERIODIC TRENDS• Reactivity: how easily a metal atom loses its electron

(ionization energy). The more reactive the metal the easier it bonds to a nonmetal.

• The Chart below shows the reactivity trend for Metals. It is the opposite for Nonmetals.

Decreases

Increases

PERIODIC TRENDS• Electronegativity- Tendency of an atom to pull

electrons which are bonded close to itself and add them to its valance orbit

• The most electro negative element is Fluorine Increases

Decreases

PERIODIC TRENDS• Electron Affinity- Amount of energy absorbed or

given off when an atom is forced to accept an electron

• The more negative value the higher the affinity and vise versa Increase

Decreases

PERIODIC TRENDS

• Ionization Energy- Amount of energy to remove 1 electron from an atom

Increases

Decreases

PERIODIC TRENDS

• Atomic Radius- radius “across” an atom

Decreases

Increases

PERIODIC TRENDS

• Shielding- a barrier made of inner-shell electrons which serves to decrease the pull of the nucleus on outer electrons

Constant

Increases

WHAT IS THE MOST ELECTRONEGATIVE ELEMENT?

WHICH ELEMENT HAS THE HIGHEST ELECTRON AFFINITY

• Li

• C

• O

• Fr

WHICH METAL IS MOST REACTIVE?

• Rb

• Li

• Al

• O

• Ca

WHICH ELEMENT HAS THE LEAST AMOUNT OF SHIELDING?

• K

• Te

• C

• He

• N

WHICH NONMETAL IS THE MOST ELECTRONEGATIVE?

• C

• P

• Ca

• Na

• At

WHAT IS THE MOST REACTIVE NONMETAL

• Cl

• Ga

• Se

• I

• At

WHICH ELEMENT HAS THE HIGHER IONIZATION ENERGY?

• N

• P

• As

• Sb

• Bi

• Positive Ions ace called Cations. They have more protons then they have electrons. Metals always lose electrons.

• Negative ions are called Anions. They have gained more electrons in their valance energy level and therefore have more electrons then protons.

OXIDATION NUMBERS• Oxidation Number- The overall charge on an ion

after It has lost electrons (metals) or gained electrons (nonmetals)

• It is easier to memorize the family trends for the oxidation numbers

• The oxidation number of an atom in a compound is the charge it would have if all shared electrons were assigned to that with the greatest attraction for electrons.

OXIDATION # TRENDS+1

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

RULES FOR ASSIGNING OXIDATION NUMBERS

• Oxidation number of an atom in its free element for is “0”

• The oxidation stat of a monoatomic ion is equal to its charge

• The sum of oxidation numbers in a neutral molecule is “0” and an Ion is equal to the stated charge

• Group 1 always have an oxidation number of 1+ Group 2 have a 2+ ect.

Cu Oxidation number is “0”

Ca2+ “2+” ox #

H2O H ox# “1+” O ox# “2-“

(so we needed 2 H to count for O’s charge)

NaCl Na ox# “1+” Cl ox# “1-“

COMPOUNDS WITH OXIDATION NUMBERS

• When ions (charged elements) are combined together forming compounds, the overall charge of the compound which results must be neutral or “0”

• In order to do this sometimes you might need to change the ratio of elements in the compound

Mg2+ Cl1-

MgCl2

WEIGHTING CHEMICAL FORMULAS

• Split the ions up into its components

• Assign Oxidation numbers to each individual element

• Cross your oxidation numbers and make note of ration

• Check if it “zero’s” out

• Wright compound formula Wright the metal ion FIRST and the nonmetal LAST

WRIGHT THE CORRECT FORMULA FOR THE A COMPOUND BETWEEN THESE TWO ELEMENTS:

• Lithium and Florine

• Calcium and Sulfur

• Cesium (#55) and Oxygen

• Potassium and Chloride

• Sodium and Oxygen

• Calcium and Bromine

IONIC COMPOUNDS

• Ionic compounds- compounds made of

• A Metal and Nonmetal

• Metal and Polyatomic Ion

• Ammonium Ion (NH4) and Nonmetal

• Ammonium Ion (NH4) and a Polyatomic Ion

BINARY NAMING OF IONIC COMPOUNDS

• Binary Naming is naming of 2 elements only

• First: call the entire name of the metal

• Then: shorten the name of the nonmetal and add “ide” as a suffix

KCl Potassium Chloride

EXAMPLE OF “IDE” ENDINGS

• Fluorine- Fluoride

• Sulfur- Sulfide

• Bromine-Bromide

• Nitrogen- Nitride

• Oxygen- Oxide

• Phosphorus- Phosphide

• Iodine- Iodide

• Chlorine- Chloride

NAME THE FOLLOWING IONIC COMPOUNDS:

• MgBr2

• NaF

• ZnS

• Na2O

• K3N

• Al2O3

TRANSITION METALS RULES

• Each transition metal has multiple oxidation numbers

• When naming these you must use the latin names and the “ic and ous” naming system

• Use the ic suffix for the highest oxidation number

• Use the ous suffix for the lowest oxidation number

EXAMPLES

• Copper (+2 & +1)

• Iron (+3 & +4)

• Lead (+4 & +2)

• Tin (+4 & +2)

• Mercury (+2 & +1)

• Cupric and Cuprous

• Ferric and Ferrous

• Plumbic and Plumbous

• Stannic and Stannous

• Mercuric and Mercurous

IUPAC NAMING• IUPAC (International Union of Practical and Applied

Chemistry)

• IUPAC came up with a naming system for these transition metals that included metals with more then 2 different charges they called it “Stock naming”

• Uses a metal’s name followed by a Roman numeral in parentheses which indicates its oxidations number

Cu2+ would be called copper (II)

WRITE THE CORRECT FORMULA:

• Iron (III) Oxide

• Tin (IV) Chloride

• Lead (IV) Oxide

• Tin (II) Sulfide

• Mercury (II) Bromide

• Iron (II) iodide

HOW DO YOU KNOW WHICH OXIDATION NUMBER TO USE IF YOU ARE GIVEN A FORMULA

AND ASKED TO NAME THE COMPOUND?

• Check your NEGATIVE ION’S oxidation number. These never change

• Once you've figured out the negative oxidation number you make the compound’s overall charge neutral unless specified otherwise.

• Pay attention to your ratios!!!!!

FeO Iron (II) Oxide

WHAT IF YOUR RATIO IS NOT 1:1

• Still Check the negative ion first, But keep in mind the ratio (stoichiometry) and multiply the OXIDATION NUMBER by the RATIO.

• Once you found the new total negative oxidation number then you can find the positive oxidation by making the compound neutral.

SnS2

SnS2Sulfur -2 oxidation number But there are 2 Sulfur Ions So the new oxidation number -2 x 2 = -4

The overall oxidation is neutral. So in order to

make -4 “0” the Tin (Sn) +4.

Tin (IV) Sulfide

NAME THE FOLLOWING COMPOUNDS WITH STOCK NAMING:

• FeCl2

• SnO

• Hg2I2

• CuI

• PbO2

POLYATOMIC IONS

• Polyatomic Ions- Ions which are imposed of several different elements

• These elements stay together in a chemical reaction and the entire group has an oxidation number or charge

• I STRONGLY ADVISE YOU MEMORIZE THESE ASAP!!!!

• When writing a polyatomic ion in a compound if you have a subscript you must put your Polyatomic Ion in parenthesis then the subscript outside of it.

Al(NO3)3 SubscriptPolyatomic

Ion

POLY ATOMIC ION CHART

WRITE THE CORRECT FORMULA FOR EACH OF THE FOLLOWING COMPOUNDS:

• Aluminum Nitrate

• Copper (II) Sulfate

• Zinc Chlorate

• Silver Nitrite

• Aluminum Permanganate

NAMING MOLECULAR COMPOUNDS

• These compounds are made up of 2 nonmetals

• When Naming these compounds use a prefix to indicate the number of atoms of each element presents

• Do not use prefixes in IONIC compounds

• Outside of Prefixes keep the first metals name the same then add the suffix “ide” onto the end of shortened second metal

1. No prefix needed or use mono 2. Di 3. Tri 4. Tetra 5. Penta

6. Hexa 7. Hepta 8. Octa 9. Nona 10.Deca

Prefixes:

NAME THE FOLLOWING MOLECULAR COMPOUNDS:

• N2O5

• SO3

• CO

• P4O10

• As2O3

HYDROCARBONS (A LITTLE ORGANIC CHEMISTRY)

• Organic Chemistry is basically the chemistry of Carbon

• Hydrocarbons are Carbon chains with Hydrogens attached to them

• There are 2 types of Hydrocarbon chains:Cyclic Chain: Cyclopentane Straight Chain: Pentane

HYDROCARBONS STRAIGHT CHAINS NAMING

• General Formula for recognition: CxH2x + 2 • Once you've identified it as a straight chain: you

count the number of Carbons

• Use the same prefixes as did in molecular compounds from 5-10 then add the suffix “ane” on the end

• For hydrocarbons with 1-4 carbons you will just have to memorize the prefix

1.Methane 2.Ethane

3.Propane 4.Butane

Carbons 1-4PentaneC5H12

CYCLIC HYDROCARBONS

• Formula for Recognition: CxH2x

• The smallest Cyclic structure has 3 Carbons

• When naming theses structures you count the amount of Carbons and use the same name as the straight chain hydrocarbons

• EXCEPT: You add the prefix “cyclo”

CyclooctaneC8H16

CyclohexaneC6H12

NAME THE HYDROCARBONS

• C3H6

• C5H12

• C8H18

• C4H8

• C7H16

• C5H10

Hint: remember to find out the equation for both straight chain and cyclic hydrocarbons

CxH2x

CxH2x + 2

WRITE THE CHEMICAL EQUATION:

• Cyclohexane

• Ethane

• Cyclobutane

• Decane

Hint: remember the equation for both straight chain and cyclic hydrocarbons

CxH2x

CxH2x + 2

DIATOMIC’S

• There are 7 elements that cannot exist by themselves as single atoms, these are known as the diatomic

• They occur naturally in the world just in pairs

• All these elements in their purest forms combine with each other (having a 2 subscript next to them).

• These elements conveniently make a 7 on the periodic table besides Hydrogen

Br2 O2H2

DIATOMICS TRENDS

REMEMBER WHEN NAMING COMPOUNDS

• First What kind of compound is it?

• Ionic (metal and nonmetal)

• Molecular (nonmetal and nonmetal)

• Polyatomic

• Hydrocarbons

• Then: Find out the ratio of atoms and/or oxidation number

• Then: follow rules for each set of compounds