Q2.82P - Chemistry: Molecular Nature Of Matter And Change

Question

For what type(s) of compound do we use Greek numerical prefixes in the name?

Step-by-Step Solution

Answer

Hydrated ionic compounds have a specific number of water molecules associated

with each formula unit.

Also, covalent compounds have Greek numerical prefixes to indicate the number of

atoms of each element in the compound.

Step 1: Explanation

Hydrated ionic compounds have a specific number of water molecules associated

with each formula unit. In systematic names this number is indicated by Greek

numerical prefix such as di, tri, tetra etc., before the word hydrate.

Covalent compounds have Greek numerical prefixes to indicate the number of atoms

of each element in the compound. The first word has a prefix only when more than

one atom of the element is present. 

Step 2: Example

Name	Formula	Systematic name
Gypsum	$CaS{O}_4.2H_{2}O$	Calcium sulfate di-hydrate
Epsom	$MgS{O}_4.7H_{2}O$	Magnesium sulphate hepta-hydrate