Question

A. What is the pH at the equivalence point of a titration of 0.050 M HClO4 with 0.025 M Sr(OH)2? Why should this be an easy question!?

B. A 25.0 mL sample of 1.44 M NH3 is titrated with 1.50 M HCl. Choose an appropriate indicator for this titration. Justify your answer.

Answer 1

A) Sr(OH)2     +   2HClO4   -----------------> 2H2O   + Sr(ClO4)

this is strong acid strong base titration.   for strong acid strong base titration at equivalent point ph is always 7.0 only no need to do calculations.

B) NH3   and   HCl    is strong acid and weak base titration such titration. pH at end point between 3 to 6. for such titration methyl orange ( pH range 3.1 to 4.5) , methyl red (ph range 4.2 - 6.3) bromophenol blue (3.1 -4.6) are thus the suitable indicators.