Question

Which is true about the pH values of a 1.0 M solution of HCl (a strong acid) and a 1.0 M solution of HC2H3O2 (a weak acid)?
A. pH values are the same because both solutions have 1.0 M concentrations.
B. pH values are different because the HCl solution partially ionizes and the HC2H3O2 solution ionizes 100 percent.
C. pH values are different because the HC2H3O2 solution partially ionizes and the HCl solution ionizes 100 percent.
D. pH values are the same because HCl and HC2H3O2 both donate one hydrogen ion per molecule.

Answer 1

Answer:

C. pH values are different because the $HC_2H_3O_2$ solution partially ionizes and the HCl solution ionizes 100 percent.

Explanation:

Strong acids are the acids which completely ionizes in the solution while weak acids are the acids which ionizes partially in the solution. They exists in equilibrium in the solution with their respective ions.

Thus, strong acids furnish greater concentration of protons as compared to weak acid when same concentration of both types are taken.

Also, pH is the negative of the logarithm  of the hydrogen ions. Thus, hydrogen ion concentration for both acids are different and thus pH will be different.