1. Write the balanced chemical equation:

NaOH (aq) + HNO₃ (aq) → NaNO₃ (aq) + H₂O (l)

2. Determine the mole ratio from the balanced equation:

The balanced equation shows a 1:1 mole ratio between sodium hydroxide (NaOH) and nitric acid (HNO₃). This means that 1 mole of NaOH is required to neutralize 1 mole of HNO₃.

3. Calculate the moles of NaOH needed:

Since the mole ratio is 1:1, you will need the same number of moles of NaOH as you have moles of HNO₃.

Therefore, you need 0.20 moles of sodium hydroxide to neutralize 0.20 moles of nitric acid.