Question

What is the concentration (in units of moles/liter) of hydrochloric acid (HCl) in a solution based on a titration experiment, in which 25.00 mL of 0.10 M sodium hydroxide (NaOH) solution is required to neutralize 20.00 mL of the HCl solution?

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 NaOH and HCl:NaOH + HCl  NaCl + H2OFrom the balanced equation, we can see that the mole ratio between NaOH and HCl is 1:1.First, we need to find the moles of NaOH used in the titration:moles of NaOH = volume  L   concentration  moles/L moles of NaOH = 0.025 L  0.10 moles/L = 0.0025 molesSince the mole ratio between NaOH and HCl is 1:1, the moles of HCl that reacted with NaOH are also 0.0025 moles.Now, we can find the concentration of the HCl solution:concentration  moles/L  = moles of HCl / volume of HCl solution  L concentration  moles/L  = 0.0025 moles / 0.020 L = 0.125 moles/LThe concentration of the HCl solution is 0.125 moles/L.