Final answer:
The 50 mL of a 0.20 N HCl solution contains more acid, has a higher hydronium ion concentration, and a lower pH than the 50 mL of a 0.20 N acetic acid solution because HCl is a strong acid and dissociates completely, whereas acetic acid is a weak acid and does not.
Step-by-step explanation:
The question asks which solution contains more acid, whether it's 50 mL of a 0.20 N HCl solution or 50 mL of a 0.20 N acetic acid solution. It also inquires about the higher hydronium ion concentration and which has a lower pH value. To address this, we need to understand the nature of the acids in question.
HCl (hydrochloric acid) is a strong acid, which means it dissociates completely in water. This leads to a hydronium ion concentration equivalent to the concentration of the HCl itself. In the case provided, a 0.20 N HCl solution will result in a 0.20 N concentration of hydronium ions in the solution.
In contrast, acetic acid is a weak acid and does not dissociate completely. A 0.20 N solution of acetic acid will have a much lower concentration of hydronium ions than the molarity suggests due to its partial dissociation, described by its dissociation constant (Ka).
Therefore, the solution of 0.20 N HCl has a higher hydronium ion concentration and thus, a lower pH compared to the 0.20 N acetic acid solution. The pH is directly related to the hydronium ion concentration, with a higher concentration resulting in a lower pH value. Given that HCl is a stronger acid and dissociates fully, the HCl solution's pH is lower than that of the acetic acid solution.