Q95P - Chemistry: Molecular Nature Of Matter And Change

Question

Correct each of the following names

a. CuI is cobalt(II) iodide

 b. $\mathbf{Fe}\left({\mathrm{HSO}}_4\right)$is iron(II) sulfate.

 c. ${\mathbf{MgCr}}_{\mathbf{2}}{\mathbf{O}}_{\mathbf{7}}$is magnesium dichromium heptaoxide.

Step-by-Step Solution

Answer

1. The correct name is copper (I) iodide.
2. The correct name is iron (III) hydrogen sulfate.
3. The correct name is magnesium dichromate.

Step 1: Name of CuI

The compound is an ionic compound. Copper ions can have many forms. 

The charge of iodine is -1 and the subscripts will just interchange as charges of these elements.

 $\mathbf{Cul}\mathbf{\to }{\mathbf{Cu}}^{\mathbf{1}\mathbf{+}}{\mathbf{l}}^{\mathbf{1}\mathbf{-}}$

The cation is copper(I) and the anion is iodide. So the name of the compound is copper(I) iodide.

Step 2: Name of Fe(HSO 4 ) 3

The compound is an ionic compound. Iron ions can have two forms, either +2 or +3.

The charge ${\mathbf{HSO}}_{\mathbf{4}}$ is -1 and the subscripts will just interchange as charges of these elements. $\mathbf{Fe}{\left({\mathrm{HSO}}_4\right)}_{\mathbf{3}}\mathbf{\to }{\mathbf{Fe}}^{\mathbf{3}\mathbf{+}}{\mathbf{HSO}}_{\mathbf{4}}^{\mathbf{1}\mathbf{-}}$

The cation is iron (III) and the anion is hydrogen sulfate and the name is iron (III) hydrogen sulfate.

Step 3: Name of MgCr 2 O 7

The compound is an ionic compound. The cation is magnesium and the anion is the polyatomic ion dichromate, so, the name of the compound is magnesium dichromate.