A student prepares a solution of hydrochloric acid that is approximately 0.1 M and wanted to determine its precise concentration. A 25.00 mL portion of the HCl solution is transferred to a flask, and after a few drops of indicator are added, the HCl solution is titrated with 0.0619 M NaOH solution. The titration requires exactly 38.90 mL of the standard NaOH solution to reach end point. What is the molarity of the HCl solution?

C(HCl) =

same ol' same ol'. Look at your aspirin, acetic acid, etc titrations. I shall be happy to address specific questions you have about these but the method of working them is the same.

M1V1=M2V2

M*25= 0.0619*38.9 = MHCl= 2.408/25
MHCl= 0.0963 M

To determine the molarity of the HCl solution, you need to use the concept of stoichiometry and the volume of the NaOH solution required to reach the end point.

Here's how you can calculate the molarity (C) of the HCl solution:

1. Write the balanced chemical equation for the reaction between HCl and NaOH:
HCl + NaOH → NaCl + H2O

2. Determine the stoichiometric ratio between HCl and NaOH from the balanced equation. In this case, the ratio is 1:1, meaning 1 mole of HCl reacts with 1 mole of NaOH.

3. Calculate the number of moles of NaOH used in the titration:
Moles of NaOH = Molarity of NaOH × Volume of NaOH solution (in liters)
= 0.0619 mol/L × 0.03890 L

4. Since the stoichiometric ratio between HCl and NaOH is 1:1, the moles of HCl is equal to the moles of NaOH used in the titration.

5. Calculate the volume of the HCl solution used in the titration:
Volume of HCl solution = Volume of NaOH solution (in liters) × (Molarity of NaOH / Molarity of HCl)
= 0.03890 L × (0.0619 mol/L / Molarity of HCl)

6. Convert the moles of HCl to molarity:
Molarity of HCl = Moles of HCl / Volume of HCl solution (in liters)
= (0.0619 mol/L × 0.03890 L) / (0.03890 L × (0. 0619 mol/L / Molarity of HCl))

Simplifying the equation, we get:
Molarity of HCl = 0.0619 mol/Molarity of HCl

Now, solve this equation to find the molarity of the HCl solution.

Note: The unit for the molarity of both HCl and NaOH will be mol/L.