Titration Experiment: Determining HCI Concentration

What experiment was conducted by a student to determine the concentration of HCI?

A student weighed out 1.054 g THAM and added it to a flask with 90mL of deionized water. After adding 3 drops of bromo-cresol green indicator, the student titrated with an unknown concentration of HCI to an endpoint of 15.6 mL. What was the concentration of the HCI used to titrate?

Answer:

The concentration of the HCl used to titrate was 0.021 M.

In the experiment, the student used THAM (tetrahydroaminoethanol) to determine the concentration of hydrochloric acid (HCl) through a titration method. By calculating the moles of THAM and the volume of HCl used, the student was able to determine the concentration of the HCl solution.

The molar mass of THAM is 152.14 g/mol. By dividing the mass of THAM used (1.054 g) by its molar mass, the student found that there were 0.0069 moles of THAM. The balanced chemical equation for the reaction between HCl and THAM was used to determine the volume of HCl needed for the titration.

From the balanced equation, it was determined that 1 mole of HCl reacts with 1 mole of THAM. By dividing the moles of THAM by the concentration of HCl used, the volume of HCl was found to be 0.33 L (or 33 mL).

Therefore, the concentration of the HCl used in the titration experiment was 0.021 M. It is important to note that the concentration could vary with different volumes of deionized water or THAM used in the experiment.