Question

What is the concentration of hydrochloric acid (HCl) in a solution, given that 25 mL of this solution requires 0.10 M sodium hydroxide (NaOH) to reach the equivalence point during a titration?

Answer 1

To find the concentration of hydrochloric acid  HCl  in the solution, we can use the concept of stoichiometry and the balanced chemical equation for the reaction between HCl and NaOH:HCl + NaOH  NaCl + H2OAt the equivalence point, the number of moles of HCl is equal to the number of moles of NaOH. We can use the formula:moles = molarity  volumeFirst, let's find the moles of NaOH:moles of NaOH = molarity of NaOH  volume of NaOHmoles of NaOH = 0.10 M  0.025 L  converting 25 mL to liters moles of NaOH = 0.0025 molesSince the moles of HCl are equal to the moles of NaOH at the equivalence point:moles of HCl = 0.0025 molesNow, we can find the concentration of HCl using the formula:molarity of HCl = moles of HCl / volume of HClAssuming the volume of HCl is also 25 mL  0.025 L , we can calculate the molarity:molarity of HCl = 0.0025 moles / 0.025 Lmolarity of HCl = 0.10 MSo, the concentration of hydrochloric acid  HCl  in the solution is 0.10 M.