JAMB - Chemistry (2024 - No. 21)
The table above shows the formulae of some ions. In which of these compounds is the formula not correct?
Aluminiumtetraoxosulphate(VI), Al\(_2\)(SO\(_4\))\(_3\)
Calciumtrioxonitrate(V), Ca(NO\(_3\))\(_2\)
Iron(III)bromide, Fe\(_3\)Br
Potassiumsulphide, K\(_2\)S
설명
Iron(III)bromide is the correct answer because Fe has a valency of +3 while Br has a valency of -1,
In the bid to form compounds, they bond together and exchange their valency.
⇒ Fe takes the valency of Br which is 1 while Br takes the valency of Fe which is 3.
Therefore, the formula for the compound formed should be FeBr\(_3\) and not Fe\(_3\)Br