Question

Does it matter if you spray a bit of water at the tip of your burette when titrating strong base into strong acid, i.e. does it change the equivalence point?

Answer 1

It decreases the concentration of your acid solution, so you may need to swirl your solution more every now and then to ensure that the titrant is distributed throughout the solution.

However, the number of `"mol"`s of titrant you need to add should not change, because the number of `"mol"`s of what you're titrating is still the same.

Say you have `"0.50 M NaOH"` to use for titrating `"0.50 M HCl"`. If you add `"100 mL"` of water to `"100 mL"` of the `"0.50 M"` solution of `"HCl"`, which has

`"0.50 mol"/"L" xx "0.10 L" = "0.05 mols H"^(+)`,

you would have `"0.25 M HCl"`, but you would still have

`"0.25 mol"/"L" xx "0.20 L" = "0.05 mols H"^(+)`

So you would still have the same `"mol"`s of what you're titrating available to match up with your titrant, and you haven't changed how many `"mol"`s you need to add of your titrant.

The difference is that what you're titrating now "harder to find", because it's a more dilute solution. You can still add titrant by dripping slowly, but you have to be more careful not to add too fast without checking, now that it's harder to successfully neutralize what you're titrating.