The Molar Concentration of HCl in a Titration Experiment
The end point in a titration of a 45ml sample of aqueous HCl was reached by addition of 30ml of 0.6M titrant.
The titration reaction is 2HCl+Ca(OH)2→CaCl2+2H2O. What is the molar concentration of HCl?
A) 0.4 M
B) 0.8 M
C) 1.0 M
D) 0.6 M
What is the molar concentration of HCl in the titration experiment? The molarity of the HCl solution can be calculated from the titration with Ca(OH)2 based on the stoichiometry of the reaction and the volume of the solution. Accordingly, the molarity of HCl is calculated as 0.2 M. Explanation: To calculate the molar concentration of HCl from a titration, we can use the stoichiometric balance equation. In this case, the reaction equation is 2HCl+Ca(OH)2→CaCl2+2H2O. For this reaction, one molecule of Ca(OH)2 reacts with two molecules of HCl. Therefore, the molar concentration of HCl will be twice that of the titrant Ca(OH)2. Given that the titrant concentration is 0.6M, the concentration of HCl would therefore be 0.6M x 2 = 1.2 M. However, as 30 ml of 0.6M Ca(OH)2 is used to titrate 45 ml HCl, the molarity of HCl solution can be calculated based on the stoichiometry of the reaction and the volume of the solution, obtaining Molarity of HCl = [30ml x 0.6M / (2 * 45 ml)] = 0.2 M. Hence, the correct answer is not provided in your options A, B, C, and D.