Manganese (II) nitrate solution is mixed with sodium hydroxide?

Question

The AP Chemistry Exam has one question that requires you to write balanced equations for chemical reactions. In all cases, a reaction occurs. Assume the solutions are aqueous unless otherwise indicated. Represent substances in solutions as ions if the substances are extensively ionized. Omit formulas for any ions or molecules that are unchanged by the reaction. You need not balance the equation.

Answer 1

Mn(NO3)2 + 2NaOH + O2 -> MnO2 + 2NaNO3 + H2O