CHEM 1411 - General Chemistry I

Course Lecture Notes

Fall 2007

 

Instructor: Dr. Shawn Amorde

web page: www.austincc.edu/samorde

 

 

 

Naming Inorganic Compounds

 

Text Chapters (2.3, 3.6-3.8, 4.5, 4.6)

Recommended Problems:  (Chpt. 3:  52, 58, 60, 62, 70, 76, 78, 80  Chpt4: 48, 52, 50, 54)

 

I.                   Naming Inorganic Compounds

A.    Names and Formulas of Ionic Compounds

B.     Naming Binary Compounds

C.     Naming Acids and Their Salts

 

 

 

Naming Ionic Compounds

 

First, remember the molecular formula is written with the positive ion first.  The names follow the same rule.  So your name always starts with the positive ion.

For example, NaCl

sodium chloride

If the ion has a +1 charge the name is just the elements name, i.e. sodium chloride.

If the ion has a +2 charge he name is the elements name followed by the charge number, i.e. calcium(II) chloride, for CaCl2.

 

We haven’t learned enough about electrons and chemical bonding for you to predict the ions charges!!  So don’t worry, just check the chart in your book (pg. 53 and 136).

 

After distinguishing your positive ion name, you follow with the negative ions name.

CaCl2, calcium(II) chloride

Again, check the chart in the book for the ion names.

Notice all of the negative ion names end in “ide” or “ate”

 

Finally, let’s go from name to formula.

calcium fluoride

 

 

 

 

 

 

zinc phosphate

 

 

 

 

 

 

 

 

Binary Compounds

 

When H is bonded to a Group 6A or 7A the resultant molecule is an acid in aqueous solutions, and is called a binary compound.

 

These are similar to the naming of ionic compounds, except H is always the positive ion.

So HCl, is hydrogen chloride

 

But when dissolved in water…..

HCl is hydrochloric acid

 

 

 

 

 

 

 

 

 

Ternary Acids

 

These are the oxoacids.  When a molecule consists of hydrogen, oxygen, and one of the metals, this is a ternary acid.

For example, H2SO4, is sulfuric acid.

 

Again, we haven’t learned enough about bonding to recognize the structural elements of this acid, but there is a chart in your book (pg. 137) which lists the common acids.

 

The important thing to remember here is that “ic” is assigned arbitrarily to these acids…..so use the chart.

One less oxygen in the molecular formula means the name changes to “ous”, i.e. H2SO3 sulfrous acid.

One less oxygen in the molecular formula means “hypo” is added to the beginning, i.e. H2SO2, would be hyposulfurous acid.

 

 

Basically, this section can be extremely confusing!!

Just remember that names of compounds are designed to enable you to write the formula from the name and vice versa. 

Pages 137 and 138 have charts of the names you will need to know.  Look at these!!

 

Oxidation Number

 

We have just discussed the “exaggerated” covalent bonds and using Formal Charge as a bookkeeping method.  The same concept is needed for our ionic bonds, this is called oxidation number.

 

Oxidation number is the charge an atom would have if the more electronegative atom took both electrons completely!!

 

Some rules;

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Aqueous Solutions

 

 

Molarity

 

We need a way for practical laboratory practices to measure reacting species in solution.  One way is to use molarity. 

 

M = mol/L

 

Remember you can use molecular weight to calculate moles and density for conversion of liquids to volume.

 

Let’s try a problem

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Dilution of Solutions

 

Remember that we can rearrange the definiton of Molarity to give volume

 

 

 

 

 

 

 

 

We can also relate this equation to dilution of solute with more than one solvent.  * Because the moles of solute doesn’t change!!

 

 

 

 

 

 

 

 

 

 

 

 

Using Solutions and calculations!!