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?

Question

Olivia Anton · Accepted Answer

Because it lowers the concentration of your acid solution, you might need to occasionally swirl it more to make sure the titrant is evenly distributed.

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.

There is a difference in that the substance you are titrating is now "harder to find" due to its increased dilution; you can still add titrant by slowly dripping, but you will need to exercise greater caution to avoid adding too much at once without first verifying that it will not successfully neutralize the substance you are titrating.

Wyatt Adkins · Answer

undefined No, spraying a bit of water at the tip of the burette during titration of a strong base into a strong acid does not significantly change the equivalence point. The small amount of water added is negligible compared to the volume of the titrant being delivered, so it does not alter the stoichiometry of the reaction or the point at which equivalence is reached.