A 35.0 mL sample of 0.150 M aqueous ammonia, NH ( )
CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
A 35.0 mL sample of 0.150 M aqueous ammonia, NH3 (Kb=1.8×10−5), is titrated with 0.300 M HCl at 25 °C.
Respond to the parts below.
(a) Calculate the volume of HCl that must be added to reach the half-equivalence point.
(b) Determine the pH at the half-equivalence point and explain its significance with respect to the acid–base pair present.
(c) Calculate the pH at the equivalence point.
(d) The indicators bromophenol blue (pH 3.0–4.6) and phenolphthalein (pH 8.2–10.0) are available. Predict which indicator would allow the most accurate detection of the end point in this titration and justify your answer based on your calculations.