A student titrates 25.00 mL of a monoprotic acid with 0.1000 M NaOH
CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases
Problem
A student titrates 25.00 mL of a monoprotic acid with 0.1000 M NaOH. The indicator chosen changes color at pH 5.0, causing the student to stop the titration when only 98 % of the NaOH required for stoichiometric neutralization has been delivered. How will this premature end point affect the molarity of the acid calculated by the student?
(a) The effect cannot be predicted without knowing the acid’s Ka value.
(b) The calculated molarity will be 2% higher than the true value.
(c) The calculated molarity will be 2% lower than the true value.
(d) The calculated molarity will be unchanged because the percent error cancels out.