Monday, Feb. 3rd: “A” DayTuesday, Feb. 4th: “B” Day

AgendaHomework questions/collectFinish Sec. 5.3: “Names & Formulas of Ionic

Compounds”In-Class: Ionic Bonding ActivityHomework:

Sec. 5.3 review, pg. 180: #1-8“What is a Polyatomic Ion?” WSConcept Review: “Names & Formulas of Ionic

Compounds”

Homework“What is an Oxidation Number?”“How are Chemical Compounds Named?”“Naming Ionic Compounds”

Questions?

Hand In

Quick Review…Remember, a binary compound is made of

just 2 elements.The simple cation is the positively charged

metal ion and is named first.The simple anion is the negatively charged

non-metal ion and is named last.But, not all ionic compounds are binary

compounds…

Polyatomic IonsInstead of having ions made of a single atom,

many ionic compounds have groups of atoms that are ions.

A simple ion is monatomic, which means “one-atom.” The prefix “poly” means many or more than one.

Polyatomic ion: a charged group of 2 or more bonded atoms that can be considered a single ion.

Polyatomic IonsTable 2 on Pg. 178 in your book lists some polyatomic ions. There are additional polyatomic ions on the back of the handout I gave you.

Examples: CO3

2- : carbonate ion OH- : hydroxide ion PO4

3- : phosphate ionThe charges on polyatomic ions are not found on any

one atom. Instead, they are spread across the entire group of covalently bonded atoms.

Naming Polyatomic IonsMany polyatomic ions contain oxygen.The endings –ite and –ate mean there is oxygen

present in the polyatomic ion.-ite means less oxygen (think LITE)-ate means more oxygen (I ATE more)

Examples:SO3

2- is sulfite (3 oxygen atoms = less oxygen)

SO42- is sulfate (4 oxygen atoms = more oxygen)

Naming Polyatomic IonsIf there is hydrogen in the polyatomic ion, the ion’s

name starts with hydrogen.The prefixes mono- and di- are used to show the

number of hydrogen atoms.“mono” means 1“di” means 2

Examples:HSO4

2- : monohydrogen sulfate (1 hydrogen)

H2SO4- : dihydrogen sulfate (2 hydrogen)

Naming Polyatomic Ions

The prefix thio- means:

“replace an oxygen atom with a sulfur atom”

Example:

K2SO4 : potassium sulfate

K2S2O3 : potassium thiosulfate

(1 oxygen atom was replaced with a sulfur atom)

Hints for writing formulas with polyatomic ions

1. Find the charges on the cation and the anion.2. Look at the tables to find the formula for the

polyatomic ion. (it can be a cation or an anion)3. Write the formula so that the charges balance

out to zero.4. If more than 1 polyatomic ion is needed to

balance the charge, put the polyatomic ion in ( ) and add a subscript outside the ( ).

Sample Problem A: pg 179Write the formula for iron(III) chromate.1.Find the charge for the iron(III) cation:

Fe3+

2.Find the formula and charge for the chromate polyatomic ion from the table:

CrO42-

3.Balance charges of cation and anion and write the formula: Fe3+ CrO4

2-

Fe2(CrO4)3

PracticeWrite the formulas for the following ionic

compounds:a) Calcium cyanide

Ca(CN)2

b) Ammonium sulfate(NH4)2SO4

c) Calcium acetateCa(CH3COO)2

d) Rubidium thiosulfateRb2S2O3

Ionic Bonding ActivityIn this activity, you will work with a partner of

your choice to construct various ionic compounds using the “ion squares” provided.

Each square contains a cation or anion.Working with your partner, construct

formulas using the elements listed under “combining substances”.

In addition to the 10 compounds listed on the handout, you need to come up with 5 of your own using the “ion squares”.

Ionic Bonding ActivityUse the table of polyatomic ions on page 178

of your textbook and the handouts for help with the names and charges of the polyatomic “ion squares”.

This activity will be graded like a lab, is worth 30 points, and will be due today!

Use your time wisely!

Combining Substances Chemical Formula

Name of Compound

Aluminum3+

Bromine1-

AlBr3 Aluminum Bromide

You will each need to make a data table to record your data.

Sample Data Table

HomeworkSection 5.3 review

Pg. 180: #1-8“What is a Polyatomic Ion? worksheetConcept Review: “Names & Formulas of Ionic

Compounds”

You will need to use your book for the tables on pgs. 162-163 or the handout I gave you for the cations/anions formed.

You will need to use the table of polyatomic ions on pg. 178 and the handouts I gave you.