Write a balanced chemical equation for the neutralization reaction between phosphoric acid and rubidium hydroxide.

Phosphoric acid is a weak acid, while rubidium hydroxide is a strong acid.

H₃PO₄ + RbOH - - > Rb₃PO₄ + H₂O

We get Rb₃PO₄ because PO₄ has a charge of 3-, that is PO₄³⁻. Rb has a charge of 1+. You give the subscript of one the charge of the other as this is an ionic compound. So you end up with Rb₃PO₄, a neutral compound.

Now let's balance the equation:

H₃PO₄ + 3RbOH - - > Rb₃PO₄ + 3H₂O