A student plans to determine the pH of a 0.10 M solution of HF ( ) by assuming that…
CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases
Problem
A student plans to determine the pH of a 0.10 M solution of HF (Ka=7.2×10−4) by assuming that the equilibrium concentration of HF remains 0.10 M. Which statement correctly evaluates this assumption?
(a) The assumption is acceptable because the percent ionization is less than 5\%.
(b) The assumption is acceptable because Ka is small compared with the initial concentration of HF.
(c) The assumption is not acceptable because the percent ionization exceeds 5\%.
(d) The assumption is not acceptable because HF behaves essentially as a strong acid at 0.10M.