Question

5. Why is it not necessary to refill your buret for the second trial if the first trial used less than 25.00 mL of titrant? What final volume would you expect your buret to show at the end of trial 2 if the titration for trial 1 required 15.00 mL?!

Answer 1

The volume of the buret is generally 50 ml.So for if the same titration for trial 1 ,if the need of titrant is less than 25 ml then it indicates that of second trial it also need less than 25 ml.

Mathematically,

after trial 1,the volume of titrant left >(50-25)ml.=25 ml.

But for second trial need also less than 25 ml as the titration is same.

After the 1st trial the ammount of the titrant left is greater than 25 ml.

So it is not necessary to refill your burret for 2nd trial if the 1st trial used less than 25.00 ml.

For the second case given

Total volume of buret =50 ml

1st trial need =15 ml

So the second trial also need = 15 ml as it is the same titration.

So the total volume used =(15 + 15) ml = 30 ml.

So the volume left after 2nd trial =(50-30)ml =20 ml.

Titrant used 40 Titrant left. Buret Show This