Potentiometry is a technique used to measure the potential difference between a working electrode and a reference electrode in an electrochemical cell. To determine the concentration of hydrochloric acid HCl in a given sample using potentiometry, you can follow these steps:1. Prepare the potentiometric setup: You will need a pH meter or a voltmeter with a high impedance , a glass pH electrode working electrode , a reference electrode e.g., Ag/AgCl electrode , a magnetic stirrer, and a beaker.2. Calibration: Before starting the experiment, calibrate the pH meter using standard buffer solutions e.g., pH 4, 7, and 10 . This will ensure accurate measurements.3. Prepare the sample: Dilute the HCl sample with distilled water to a suitable concentration range e.g., 0.01 to 0.1 M to ensure accurate measurements. Make sure to use a volumetric flask for accurate dilution.4. Measure the potential: Pour the diluted HCl sample into the beaker and immerse the glass pH electrode and the reference electrode in the solution. Make sure the electrodes do not touch each other or the bottom of the beaker. Turn on the magnetic stirrer to ensure proper mixing of the solution. Wait for the potential reading to stabilize, and then record the potential in millivolts and the corresponding pH value displayed on the pH meter.5. Determine the concentration: The potential difference between the working and reference electrodes is related to the concentration of HCl in the sample through the Nernst equation:E = E0 + 2.303 * RT/nF * log10 [H+] Where E is the measured potential, E0 is the standard electrode potential, R is the gas constant, T is the temperature in Kelvin, n is the number of electrons transferred in the redox reaction in this case, n = 1 , F is the Faraday constant, and [H+] is the concentration of hydrogen ions in the solution.Since HCl is a strong acid, it dissociates completely in water, and the concentration of H+ ions is equal to the concentration of HCl. Therefore, you can calculate the concentration of HCl in the sample using the measured potential and the Nernst equation.6. Repeat the measurements: To ensure the accuracy of your results, repeat the measurements with different dilutions of the HCl sample and calculate the average concentration.By following these steps, you can determine the concentration of hydrochloric acid in a given sample using potentiometry.