Naming/Writing Ionic , Covalent , Acidic Compound

Ionic Compound:

Ionic compounds are formed when a metal gives up its electrons to a non-metal. So , to name the ionic compound we apply these rules :

The metal ion's name + the non-metal's name ends in ide.

Ex:

AlCl₃ = aluminum chloride

Na₂S = sodium sulfide

K₂O = potassium oxide

MgH₂ = magnesium hydride

Way to write the formula of an ionic compound

We have to make sure that the sum of charges = 0

Ex: Ca⁺² and P^-3

One of each would create a sum of 2 + (-3) = -1. To get a sum of zero, we need three Ca⁺² ions and two P^-3 for a total of 3(2)+ 2(-3) = 0.

So the answer is Ca₃P₂

Polyatomic Ions

Polyatomic Ion	Name
OH-1	hydroxide
SO4-2	sulfate
PO4-3	phosphate
NO3-1	nitrate
CO3-2	carbonate
HCO3-1	hydrogen carbonate or bicarbonate
ClO3-1	chlorate
NH4+1	ammonium

Ionic Compounds formed by a metal which has more than one charge

We apply this rules :

Metal element's name + ( charge in roman number ) + name of non-metal element + ide

Example:

Cu₂O = Copper (I) oxide

CrCl₃ = chromium (III) chloride

Covalent Compound: These are formed from non-metals that share electrons.

We apply these rules:

Prefix + First element's name + Prefix + Second element with “ide " ending.

For this we use a set of prefixes:

mono di tri tetra penta hexa hepta octa nona deca

1 2 3 4 5 6 7 8 9 10

Examples: CO = carbon monoxide (note we don't say monocarbon monoxide)

CO₂ = carbon dioxide

N₂O₅ = dinitrogen pentoxide

PCl₃ = phosphorus trichloride

Acid :

1. Naming the simple acid :

Hydro + name of the second element with “ ic “ in the end + acid

Ex: HCl = Hydrochloride acid

HBr = Hydrobromide acid

2. Naming the complex acid :

- Change the suffix of the polyatomic ion:

If the suffix is ate, change to “ic “

If the suffix is ide, change to “ous “

- Add acid in the end

Ex:

H2SO4 : sulphuric acid

HClO4 : perchloric acid

H2SO3 : sulphurous acid