Chemistry : Learn how to Be able to write Covalent not to mention Ionic Chemical Formulas.

Writing chemical formulas is an essential skill if you are going to be successful in chemistry. Balancing equations, predicting reactions and calculating stoichiometric problems all rely on your ability to properly write a chemical formula. In the event that you produce a mistake in the formula it'll affect the balancing and the mole ratios used to execute stoichiometric calculations. So take the time to discover ways to properly write chemical formulas, you'll be glad you did.

What You Need certainly to Know...

1. Just how to use the Periodic Table
2. How to utilize 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 include two parts (binary) and are classified as ionic or covalent. CAS 174063-87-7 The overall rule for naming and writing compounds is to put the more metallic element first followed by the less metallic element. Remember to utilize subscripts to show how many atoms or ions contained in the formula.

Writing Ionic Formulas

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

• If the charges are (2+) and (3-) the sum is (1-) and is not balanced. But the cheapest common multiple of 2 and 3 is 6. So using subscripts increase how many cations by 3 and how many 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 correct charge is indicated by way of a Roman numeral placed following the cation's name. Remember to treat polyatomic ions as complete unit, do not 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 by the more electronegative element and use subscripts to point how many atoms present. Remember that prefixes are employed only with covalent compounds.

EXAMPLE #1: carbon dioxide 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 is to writing chemical formulas. So you need to rehearse, practice and practice some more. Although chemical formulas aren't all that hard, you will need to rehearse if you are going to be any good at it.