Final answer:
The pH of 0.041 M HCl is 1.4, which can be calculated using the formula pH = -log[H3O+]. This answer is not among the provided options, indicating an error in the question. Equimolar solutions of HCl and HC2H3O2 have different pH values because HCl is a strong acid and fully ionizes, while HC2H3O2 is a weak acid and only partially ionizes.
Step-by-step explanation:
The pH of 0.041 M HCl can be calculated using the formula pH = -log[H3O+]. Since HCl is a strong acid, it fully ionizes in solution, and the concentration of hydronium ions [H3O+] is equal to the concentration of HCl. Thus, pH = -log(0.041) which gives a pH of 1.39 (rounding to the correct number of significant figures, the answer would be 1.4). This answer is not given in the multiple choices, indicating there might be an error in the available options or in the question. The provided options for the pH of 0.041 M HCl are not correct based on this calculation.
Regarding the second question, equimolar solutions of HCl and HC2H3O2 do not have the same pH for the following reasons:
- Different dissociation constants: HC2H3O2 has a smaller dissociation constant compared to HCl.
- HCl is a strong acid, while HC2H3O2 is a weak acid, which means that HCl ionizes completely in solution, but HC2H3O2 only partially ionizes.