[ArinneX]

Hi, I am writing a lab report for an equilibrium experiment involving titration of KHP, KHT with NaOH. I have my 3 concordant titres and have worked out the average. the next part of the question asks for "half range titre". I nhave been through all my course materials and cannot find any mention of this. I am assuming this is in relation to the uncertainty and not half of the titre value as the next part of the question asks for the titre volume and uncertainty value. I keep looking at it and it feels wrong but I cant find anything to explain it. Also for the propagation of errors I have been adding the uncertainty values but cant find information on what to do for an average i.e if I have uncertainty of 0.04 in 3 readings propagating to 0.12 but I'm pretty sure when the reading are divided by 3 to get the average the uncertainty does not divide by 3. I could add the percentages but shouldn't the uncertainty value decrease in an average?

[Borek]

My gut feeling is it is about just half the titre, as used for pKa determination.

[ArinneX]

ok that would make sense, I was not aware half range of the titre was needed to find the equilibrium constant. I cant see it used anywhere on the lab proforma, although I haven't finished filling it out yet but it must be what it is asking for then. Thankyou for replying I am finding it hard having to learn all this online.