Question

What is the concentration of a solution of hydrochloric acid (HCl) in moles per liter (M) if 25 milliliters of the HCl solution reacts completely with 35 milliliters of a 0.1 M solution of sodium hydroxide (NaOH) during a titration process?

Answer 1

To find the concentration of the HCl solution, we can use the concept of stoichiometry and the balanced chemical equation for the reaction between HCl and NaOH:HCl aq  + NaOH aq   NaCl aq  + H2O l From the balanced equation, we can see that one mole of HCl reacts with one mole of NaOH. We are given the volume and concentration of the NaOH solution, so we can find the moles of NaOH:moles of NaOH = volume  L   concentration  M moles of NaOH = 0.035 L  0.1 M = 0.0035 molesSince the ratio of HCl to NaOH is 1:1, the moles of HCl that reacted are also 0.0035 moles. Now we can find the concentration of the HCl solution using the volume of the HCl solution:concentration of HCl = moles of HCl / volume of HCl  L concentration of HCl = 0.0035 moles / 0.025 L = 0.14 MSo, the concentration of the HCl solution is 0.14 M.