1.

The calculated moles of KHP will be too high, because if the molar mass of the KHP is impure at the beginning. The calculated amount of NaOh needed for neutralization will be too low. Molarity of NaOh will end up being too high.

2.

If the NaOH is uncapped, the CO2 from air might react with it…the concentration of NaOH will be reduced.

3.

The molar concretion will be higher than normal, the reported percentage of acetic acid is higher.

4.

Water added to KHC8H4)4 will never have an effect, the number of moles will never change.
If you add water to naOH, it will change thte concentration and effect the number of moles used in titration.

5.

t doesn’t effect the molar concentration because the NaOh is hydroscopic. The concretion will remain unaffected.

6.

It will be too low. The molar concretion of NaOH, HCl will report fewer than needed or present. If you used too much NaOH, your calculated strength is too weak. The endpoint is where pink stays for 30 seconds after titration, if it gets too dark, it is too weak, too light, and it is too strong.