Many chemical names are similar at first glance. Give the formulas of the species in each set: (a) ammonium ion and ammonia; (b) magnesium sulfide, magnesium sulfite, and magnesium sulfate; (c) hydrochloric acid, chloric acid, and chlorous acid; (d) cuprous bromide and cupric bromide.

The formulae are

a) ammonia : NH₃

ammonium ion: NH₄⁺

b) Magnesium sulfide: Mgs

Magnesium sulfite: MgSO₃

c) Hydrochloric acid: HCl

chloric acid: HClO₃

chlorous acid: HClO₂

d) cuprous bromide: CuBr

cupric bromide: CuBr₂

Explanation:

The formula are

a) ammonia : NH₃ and when ammonia gains a proton it becomes

ammonium ion: NH₄⁺

b) Magnesium sulfide: MgS : the sulfide group is S⁻²

Magnesium sulfite: MgSO₃ : the sulfite group is SO₃⁻²

c) Hydrochloric acid: HCl:

chloric acid: HClO₃ These are oxy acids

chlorous acid: HClO₂

d) cuprous bromide: CuBr : cuprous word is used for copper with one positive charge

cupric bromide: CuBr₂: cupric is used for di-positive copper

a) Ammonium ion: NH₄⁺, ammonia: NH₃.

b) Magnesium sulfide: MgS, magnesium sulfite: MgSO₃, magnesium sulfate: MgSO₄.

c) Chloric acid: HClO₃, chlorous acid HClO₂.

d) Cupric bromide: CuBr₂, cuprous bromide: CuBr.

Explanation:

a) Ammonia is the neutral substance, which as molecular formula NH₃ when it gains a proton, it becomes the ammonium ion NH₄⁺.

b) In the name of salts, first, it comes the cation name, in this case, all the cations are the magnesium (Mg²⁺). The ions of sulfur can be oxidized or not, the termination "ide" indicates the non-oxidized ion (S⁻²), "ite" the less oxidized (SO₃⁻²), and "ate" the more oxidized (SO₄⁻²). To do the molecular formula, the charges are replaced without the signals and put down. If they are equal, the number is not put.

Magnesium sulfide: MgS

Magnesium sulfite: MgSO₃

Magnesium sulfate: MgSO₄

c) The acids can be oxidized or not, when it has no oxygens, the name is given "hydro" + the anion name, as hydrochloric acid (HCl). When there's oxygen in the molecule, the more oxidized is name as "'per" + anion name + "ic", the second more oxidized as anion name + "ic", the second less oxidized as anion name + "us", and the less oxidized as "hypo" + anion name + "us". In this case:

chloric acid: HClO₃

chlorous acid HClO₂

d) The salts of copper are named depends on the oxidation number of the cupper. The one with a higher oxidation number (+2) is called cupric, and the other (+1), cuprous. Thus:

cupric bromide: CuBr₂ (oxidation number = + 2)

cuprous bromide: CuBr (oxidation number = + 1)