[JonD]

When calculated the % purity of the impure KHP, a student read the buret as 14.5 mL of NaOH rather than 15.5 mL. What effect would that have on the answer to the % purity? (lower, higher, same)

[Donaldson Tan]

NaOH is used to titrate with the impure KHP to find out how much KHP is in the impure sample. Since the amount of NaOH consumed by the titration is directly proportional to the amount of KHP in the sample, then an erred reading of a smaller value for the amount of NaOH would translate to an under-measurement of the amount of KHP in the sample. This means the % purity of the sample will be mis-calculated as a lower value.

[Donaldson Tan]

warning: no double posting

you posted the same topic in the general chemistry section. I've deleted your post at the general chemistry section. Please read the forum policy. It's not a large chunky text - just a list of do's and dont's.

cheers, mate.