To find the concentration of the HCl solution, we can use the balanced chemical equation for the neutralization reaction between HCl and NaOH:HCl aq + NaOH aq NaCl aq + H2O l From the balanced equation, we can see that the mole ratio between HCl and NaOH is 1:1. This means that the moles of HCl required to neutralize the NaOH is equal to the moles of NaOH.Given that 0.015 moles of NaOH are neutralized, we also have 0.015 moles of HCl.Now, we can use the formula for concentration:Concentration mol/L = moles of solute / volume of solution L First, we need to convert the volume of the HCl solution from mL to L:25.00 mL = 0.025 LNow, we can calculate the concentration of the HCl solution:Concentration mol/L = 0.015 moles / 0.025 L = 0.6 mol/LSo, the concentration of the HCl solution is 0.6 mol/L.