How many milliliters of a 0.1 Molar NaOH solution is needed to neutralize 1 liter of lemonade containing 25% citric acid?

I assume this is 25% w/v. 25% w/v citric acid means 25 g citric acid in 100 mL soln or 250 g citric acid in 1000 mL.

Convert 250 g citric acid to moles (moles = grams/molar mass).
2. Write the equation.
3. Using the coefficients in the balanced eqaution, convert moles H^+ in citric acid to moles NaOH.
4. MNaOH = moles NaOH/L NaOH.
Solve for L NaOH and convert to mL.