ionic compounds - ms. goldenberg

Univalent, Multivalent, Polyatomic, Binary acid, Oxyacid, Hydroxide bases, Bicarbonate bases

Ionic Compound Nomenclature

+ =

Na Cl NaCl

Definition of Compounds

pure substance two or more elements chemically combined

Types of Compounds

Grade 9 definitions Ionic compound: consists of a metal

and nonmental

Molecular compound: consists of 2 nonmetals

Ionic Compounds It is more accurate to say that ionic

compounds form when atoms transfer electrons

Ionic compounds consists of: ions of opposite charges an electron donor and acceptor

Molecular Compounds

It is more accurate to say that molecular compounds form when atoms share electrons

There is no donor or acceptor

(We will study this in more detail in another lesson)

+ =

Na Cl NaCl

Example of Ionic CompoundFormation of NaCl, or table salt

Example of Ionic Compound Sodium has 1 valence electron and

wants to remove it to be stable Chlorine has 7 valence electrons and

wants to gain one to be stable Thus, one electron from sodium is

transferred to chlorine

Na Cl

Ionic Compound

A cation will react with an anion to acquire a full valence shell

The attraction between the cation and the anion is known as an ionic bond

Na Cl

Properties of Ionic CompoundAt room temperature, most are hard,

brittle solids that can be crushed

Properties of Ionic Compound

Ionic compounds form crystals that have an alternating arrangement of positively charged ions and negatively charged ions

When they break their edges are well-defined


In an ionic crystal, every ion is attracted to every other ion

Thus, ionic crystals have very high melting points

Eg. NaCl melts at 800oC


When an ionic compound dissolves in water, the crystal structure breaks down and the ions become free to move.


Solutions of ionic compounds can conduct electricity

Nomenclature

A system used to name things In this case, we will be naming a

variety of different types of ionic compounds: Univalent Multivalent Polyatomic Acids: Binary & Oxyacid Bases: Hydroxide & Bicarbonate

Univalent & Multivalent Ions

Univalent ions: Ions that only have one possible charge

Multivalent ions: Ions that have two or more possible charges

Univalent & Multivalent Compounds

Univalent compounds: Compounds where the cation only has one possible charge

Multivalent compound: Compounds where the cation has more than one possible charge

** Only some metals are multivalent

Naming Univalent Ionic Compounds

1. Name the cation first• Cations have the same name as the element name

2. Name the anion second• Anions change the ending of its name changes to “ide”

3. Subscripts can be ignored when determining the name

(Chemical Formula--> Chemical Name)

Examples: KBr, Na3P, ZnF2


1. Identify the charges of the Ions

2. Determine the number of positive and negative ions needed to make the compound neutral

3. Use the lowest common multiple

(Chemical Name -->Chemical Formula)

Examples: Calcium Chloride

RULE for all compounds

Although ionic compounds are made of charged particles, the compound itself has no net charge

All ion charges must be equal and add up to zero

Aluminum oxide

• What are the charges on the ions?

• How many of each do we need to make the compound neutral?

• Write the chemical formula using subscripts as needed.


Calcium oxide




• Use the lowest common multiple


Multivalent Ionic Compounds

Multivalent compound: Compounds where the metal ion has two or more possible charges.

Naming Multivalent Ionic Compounds

1. Identify all the possible charges of the ions

2. Determine which charge on the multivalent ion is needed to make the compound neutral

3. Name the cation• Indicate the charge in brackets using Roman numerals

(I,II,III,IV)

4. Name the anion• Change the ending to ‘ide’

(Chemical Formula--> Written Name)Examples: FeO, Cu2S


CoCl2, MnCl41. Identify all the possible charges of the ions

2. Determine which charge on the multivalent ion is needed to make the compound neutral

3. Name the metal ion • Indicate the charge in brackets using Roman numerals

(I,II,III,IV)

4. Name the non-metal ion • Change the ending to ‘ide’


Cobalt (II) Chloride




Writing Chemical Formula for

Multivalent Ionic CompoundsBismuth (V) Phosphide




Polyatomic Ions Poly = 2 or more Atomic = atoms

A polyatomic ion is a group of atoms, usually of different elements, that act as a single ion

Example: one atom of sulphur and four atoms of oxygen form the polyatomic ion called sulphate, or SO4

2-

Name Formulaammonium NH4

+

carbonate CO32-

bicarbonate HCO3-

hydroxide OH-

nitrate NO3-

nitrite NO2-

permanganate MnO4-

phosphate PO43-

phosphite PO33-

sulphate SO42-

sulphite SO32-

Polyatomic Ions

Polyatomic Ions Similar polyatomic ions are named using the

suffixes “-ate” or “-ite”

Example: NO3- is nitrate NO2- is nitrite

Most common polyatomic ions have a negative charge

Exception: ammonium ion (NH4+) has a positive charge

Naming Polyatomic Ionic Compounds

LiHCO31.Name the cation:

2. Identify the polyatomic ion (Use table)

3.Combine the names. Do not change the polyatomic ending.


FeSO31. Name the cation:

2. Identify the charge of the multivalent ion used for the compound to be neutral. Indicate the charge using I,II,III,IV


4. Combine the names. Do not change the polyatomic ending.


Cu(NO3)21. Name the cation:

2. Identify the charge of the multivalent ion used for the compound to be neutral. Indicate the charge using I,II,III,IV


4. Combine the names. Do not change the polyatomic ending.

Writing Chemical Formula for Polyatomic Ionic Compounds1. Identify the charge of the ions in the compound

2. Determine the number of positive and negative ions needed to make the compound neutral

3. Write the metal atom first.

4. If subscripts are needed for the polyatomic ion, place a bracket around it first. Make sure to use the lowest common multiple.

Calcium chlorate

Writing Chemical Formula for Polyatomic Ionic CompoundsArsenic (III) acetate



• Write the chemical formula using subscripts and brackets as needed.

Recognizing Acids Acids have their own special naming

system

All acids will have the word ‘acid’ in it’s name.

Examples: Hydrochloric acid Sulphuric acid Acetic acid

Recognizing Acids

All acids have a chemical formula that starts with an H

Example: HCl, H2SO4

Types of Acids

Binary or Simple acids Consist of hydrogen and a nonmetal Example: HCl

Oxyacids Consists of hydrogen and a polyatomic Example: H2SO4 Example: CH3COOH

Binary Acids

Naming rules: ‘hydro’ + nonmetal ‘ic’ + ‘acid’

Examples: HCl H3P HI

Binary Acids

Nonmetal Formula NameFluorine HF Hydrofluoric acidChlorine HCl Hydrochloric acidBromine HBr Hydrobromic acidIodine HI Hydroiodic acid

Sulphur H2S Hydrosulfuric acidPhosphorus H3P Hydrophosphoric acid

Oxyacids

Consists of a hydrogen and a polyatomic ion containing an oxygen

Naming rules: 1. Identify the polyatomic in the formula 2. Look for the oxyacid name on the

reference chart 3. add ‘acid’

**Notice that you do NOT use ‘hydro’

Oxyacids

H2SO4

1. Identify the polyatomic in the formula

2. Look for the oxyacid name on the reference chart

3. add ‘acid’

Oxyacids

HC2H3O2

1. Identify the polyatomic in the formula

2. Look for the oxyacid name on the reference chart 3. add ‘acid’

Practice

Acid name Chemical formula

HBr

Hydrophosphoric acid

H3PO4

Carbonic acid

Practice

Acid name Chemical formula

HBr Hydrobromic acid

H3P Hydrophosphoric acid

H3PO4 Phosphoric acid

H2CO3 Carbonic acid

Oxyacids

Polyatomic name Oxyacid name Relative # of

oxygensHypo---ite Hypo---ous acid -2

----ite ---ous acid -1

---ate ---ic acid reference

Per--ate Per---ic acid +1

Oxyacids

Polyatomic name Oxyacid name Formula

Hypochlorite Hypochlorous acid HClO

chlorite chlorous acid HClO2

chlorate chloric acid HClO3

Perchlorate Perchloric acid HClO4

Ionic Nomenclature Summary

X YUnivalent

cationHydrogen

(acid)Multivalent

cationAnion Polyatomic Anion

Ionic Binary acid

Ionic Oxyacid

ionic compounds - ms. goldenberg

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