The pH of 0.50 mol dm-3 solutions of HCI, H2SO4 and CH3COOH were measured. which of the following statements about the values obtained is correct?
Answer Details
The correct statement is that "the pH value of the CH3COOH was the highest." pH is a measure of how acidic or basic a solution is, and it is based on the concentration of hydrogen ions (H+) present in the solution. A lower pH indicates a higher concentration of H+ ions and a more acidic solution, while a higher pH indicates a lower concentration of H+ ions and a more basic solution. For the given solutions, HCl is a strong acid that completely dissociates in water to give H+ and Cl- ions. H2SO4 is also a strong acid that dissociates into two H+ ions and one SO42- ion. CH3COOH is a weak acid that only partially dissociates into H+ and CH3COO- ions. The pH of HCl and H2SO4 solutions will be lower (more acidic) than the pH of the CH3COOH solution because they are strong acids, and their concentration of H+ ions is higher. However, we cannot determine if they have the same pH values or not from the given information. The sum of pH values of these solutions will not be equal to 14, as this value is the pH of a neutral solution (where the concentration of H+ ions is equal to the concentration of OH- ions). The solutions given in the question are acidic, and their pH values will be less than 7. Therefore, the correct statement is that the pH value of the CH3COOH was the highest because it is a weak acid that only partially dissociates, resulting in a lower concentration of H+ ions and a higher pH value.