Question

A 64.0 ml volume of 0.25 m hbr is titrated with 0.50 m koh. calculate the ph after addition of 32.0 ml of koh at 25 ∘c.

Answer 1

Hello!

The reaction between HBr and KOH is the following:

HBr+KOH→H₂O + KBr

To calculate the amount of HBr left after addition of KOH, you'll use the following equations:

$HBr_f=HBr_i-KOH=([HBr]*vHBr)-([KOH]*vKOH) \\ \\ HBr_f=(0,25M*0,64L)-(0,5M*0,32L)=0 mol HBr$

That means that after the addition of 32 mL of KOH, there is no HBr left in the solution and the pH should be neutral, close to 7. 

Have a nice day!