Concept:pH measures hydrogen ion concentration:
pH=−log[H+]. A strong acid like HCl fully dissociates, so
[H+] equals the normality for a monoprotic acid.
Explanation:HCl is a strong acid. It dissociates completely:
HCl→H++Cl−.
Given 0.1N HCl. For a monoprotic acid, normality equals molarity. So
[H+]=0.1M.
Calculate pH:
pH=−log(0.1)=−(−1)=1.0.
Other options are wrong: pH 11 or 10 indicate a basic solution, not for an acid. pH 2.0 would require
[H+]=0.01 M, which is ten times weaker.
Thus, 0.1N HCl gives pH approximately 1.0.
Answer:Option B: 1.0