Answer: The distillation flask being heated in a heating mantle. The vapors condense and drip from the condenser into the flask. As the distillate begins to drop from the condenser, the temperature observed on the thermometer should be changing steadily.
The data curve for OCI-/H3O appears to be similar to C2H3O2-/H3O because protons have not dissociated with conjugate base. This conjugate base is strong and hold proton in solution while acids try to dissociate it.