1. Write the balanced chemical equation:

2 Na (s) + 2 H₂O (l) → 2 NaOH (aq) + H₂ (g)

2. Determine the mole ratio:

The balanced equation shows that 2 moles of sodium (Na) react with 2 moles of water (H₂O).

3. Calculate moles of water:

Since the mole ratio is 2:2 (or 1:1), the number of moles of water needed is equal to the number of moles of sodium.

Therefore, you need 2.5 moles of water to react with 2.5 moles of sodium.