What is the concentration of hydrogen ions in a solution with pH = 4.282? 1.92 x 10-10 M.
4.28 M
1.66 x 104 M
5.22 x 10-5 M

the answer is 0.42 is that is an option. this question provides no info

alchemy hadn't scientific methods of study, appeal to mysticism and fantasy, the knowledge of chemistry and physics were modest at that time.

alchemy was - but as new rules were discovered it either changed into chemistry or it became "unscientific".