1. Write the balanced chemical equation:

HCl (aq) + KOH (aq) → KCl (aq) + H₂O (l)

2. Determine the moles of potassium hydroxide (KOH):

* Convert the volume of KOH solution from milliliters to liters: 24.3 mL * (1 L / 1000 mL) = 0.0243 L

* Multiply the volume of KOH solution by its molarity: 0.0243 L * 0.200 mol/L = 0.00486 mol KOH

3. Use the mole ratio from the balanced equation to find moles of hydrochloric acid (HCl):

* The balanced equation shows a 1:1 mole ratio between HCl and KOH. Therefore, 0.00486 mol of KOH will react with 0.00486 mol of HCl.

4. Calculate the volume of HCl solution:

* Divide the moles of HCl by the molarity of the HCl solution: 0.00486 mol / 0.357 mol/L = 0.0136 L

* Convert the volume from liters to milliliters: 0.0136 L * (1000 mL / 1 L) = 13.6 mL

Answer: You would need 13.6 mL of the 0.357 M hydrochloric acid solution to neutralize 24.3 mL of the 0.200 M potassium hydroxide solution.