1. Balanced Chemical Equation:

The balanced chemical equation you provided is correct:

2AgNO₃ + BaCl₂ → 2AgCl + Ba(NO₃)₂

2. Mole Ratio:

The balanced equation tells us that 2 moles of AgNO₃ react with 1 mole of BaCl₂.

3. Calculate Moles of BaCl₂:

* You have 7.5 moles of AgNO₃.

* Use the mole ratio: (1 mole BaCl₂ / 2 moles AgNO₃)

* Multiply this ratio by the moles of AgNO₃: (1 mole BaCl₂ / 2 moles AgNO₃) * 7.5 moles AgNO₃ = 3.75 moles BaCl₂

Therefore, you need 3.75 moles of BaCl₂ to react completely with 7.5 moles of AgNO₃.