Question

fill in the missing words
a) washing soda is a hydrate of $na_2co_3$ that contains ten molecules of water. the systematic name is \boxed{}.
b) epsom salts is a hydrate of $mgso_4$ containing seven water molecules. the systematic name is \boxed{}.
c) one of the rare hydrates of $cuso_4$ contains one molecule of water per two units of salt (same is 0.5 molecules of water per one unit of the salt). the systematic name is \boxed{}.

Explanation:

Part (a)

To name a hydrate, we use the name of the anhydrous salt followed by the word "hydrate" with a prefix indicating the number of water molecules. For \(Na_2CO_3\) with 10 water molecules, the prefix for 10 is "deca-". The anhydrous salt is sodium carbonate. So we combine them as sodium carbonate decahydrate.

For \(MgSO_4\) with 7 water molecules, the prefix for 7 is "hepta-". The anhydrous salt is magnesium sulfate. So the name is magnesium sulfate heptahydrate.

For \(CuSO_4\) with 0.5 (or 1/2) water molecules per formula unit of the salt, we use a fraction in the name. The prefix for 1/2 is "sesqui-"? No, actually, when the ratio is 1 water per 2 salt units, we can write it as copper(II) sulfate hemihydrate (since "hemi-" means 1/2). The anhydrous salt is copper(II) sulfate.

Answer:

sodium carbonate decahydrate

Part (b)