I'm planning to conduct an experiment in which I test how fast rusting occurs with changes to the concentration of NaCl in the solution.
I want to measure that by finding the change in mass of an iron nail over time, but in order to do that I need to clean off all the rust on the nail before weighing. I have a relatively short time to conduct the experiments.
I've heard acids like phosphoric acid, oxalic acid, or citric acid will work. I'm looking for the best acid to separate the rust from the nail preferably without using steel wool or any abrasive method. I can, however, spray down the nail with distilled water if necessary. Any suggestions?