You're describing a double displacement reaction. Here's how to approach it:

1. Write the Balanced Chemical Equation

The reaction between potassium phosphate and aluminum nitrate produces potassium nitrate and aluminum phosphate:

K₃PO₄ (aq) + Al(NO₃)₃ (aq) → 3 KNO₃ (aq) + AlPO₄ (s)

2. Interpret the Stoichiometry

* Coefficients: The balanced equation tells us that 1 mole of potassium phosphate reacts with 1 mole of aluminum nitrate to produce 3 moles of potassium nitrate and 1 mole of aluminum phosphate.

3. Calculate Moles of Potassium Nitrate

Since the problem doesn't specify how many moles of potassium phosphate are reacting, we can't give a specific numerical answer. However, we can state that:

* For every 1 mole of potassium phosphate that reacts, 3 moles of potassium nitrate are produced.

Important Note: To get a specific number of moles of potassium nitrate, you'd need to know the amount of potassium phosphate that's reacting.