Chemistry -- The best way to Generate Covalent in addition to Ionic Chemical Formulas.

Writing chemical formulas is a required skill in the event that you are going to be successful in chemistry. Balancing equations, predicting reactions and calculating stoichiometric problems all rely on your own power to properly write a chemical formula. In the event that you make a mistake in the formula it will affect the balancing and the mole ratios used to perform stoichiometric calculations. So take some time to learn to properly write chemical formulas, you'll be glad you did.

What You Need to Know...

1. How exactly to use the Periodic Table
2. How to use subscripts
3. How to find out ionic charges
4. Polyatomic ions
5. Metals with multiple charges
6. Greek and Latin numeric prefixes

The General Rule

Most compounds contain two parts (binary) and are classified as ionic or covalent. The typical rule for naming and writing compounds is to place the more metallic element first followed closely by the less metallic element. Remember to use subscripts showing the amount of atoms or ions contained in the formula.

Writing Ionic Formulas

When writing the chemical formula for ionic compounds place the cation first, then your anion and check to observe that the charges balance to zero. If the charges aren't balanced, you should increase the amount of cations and anions before algebraic sum of the charges is zero.

• If the charges are (2+) and (3-) the sum is (1-) and isn't balanced. But the cheapest common multiple of 2 and 3 is 6. So using subscripts increase the amount of cations by 3 and the amount of anions by 2.


• Thus (2+) times 3 is (6+) and (3-) times 2 is (6-) and (6+) + (6-) is zero. Balanced.

If the cation has multiple charges, the proper charge is indicated by a Roman numeral placed following the cation's name. Remember to treat polyatomic ions as complete unit, don't separate them.

EXAMPLE #1: calcium chloride is CaCl2 (calcium 2+) (chlorine 1-) boost the chlorine to two.

EXAMPLE #2: lithium nitrate is LiNO3 (lithium 1+) (nitrate 1-) balanced.

EXAMPLE #3: iron (II) sulfate is FeSO4

Writing Molecular Formulas (covalent)

When writing the chemical formula for covalent compounds place the less electronegative element first followed closely by the more electronegative element and use subscripts to indicate the amount of atoms present. CAS NO.174063-87-7 Understand that prefixes are utilized only with covalent compounds.

EXAMPLE #1: co2 is CO2 (1 C) (2 O)

EXAMPLE #2: phosphorous pentachloride is PCl5 (1 P) (5 Cl)

Don't Forget to Practice

Really, that's all there's to writing chemical formulas. Now you need to practice, practice and practice some more. Although chemical formulas aren't all that hard, you will need to practice in the event that you are going to be worthwhile at it.