Question

part 3 of 5
aluminum dihydrogen phosphate:
part 4 of 5
rubidium sulfite:

Explanation:

Part 3: Aluminum Dihydrogen Phosphate

Step 1: Identify Ions and Charges

Aluminum ion is $\text{Al}^{3+}$, dihydrogen phosphate ion is $\text{H}_2\text{PO}_4^-$.

Step 2: Balance Charges

To balance $3+$ and $1-$, we need 3 $\text{H}_2\text{PO}_4^-$ ions for 1 $\text{Al}^{3+}$ ion.

Step 3: Write Formula

Combine ions: $\text{Al}(\text{H}_2\text{PO}_4)_3$.

Part 4: Rubidium Sulfite (Note: Rubidium spelling is "rubidium")

Step 1: Identify Ions and Charges

Rubidium ion is $\text{Rb}^+$, sulfite ion is $\text{SO}_3^{2-}$.

Step 2: Balance Charges

To balance $1+$ and $2-$, we need 2 $\text{Rb}^+$ ions for 1 $\text{SO}_3^{2-}$ ion.

Step 3: Write Formula

Combine ions: $\text{Rb}_2\text{SO}_3$.

Answer:

s:
Part 3: $\boldsymbol{\text{Al}(\text{H}_2\text{PO}_4)_3}$
Part 4: $\boldsymbol{\text{Rb}_2\text{SO}_3}$