why HCL is often used to remove rust and stains but not other types of acid?
- Audrey HepburnLv 71 十年前最愛解答
Usually, we use strong acids to remove rust and stains.
For usual strong acids, there are 3 types. Namely hydrochloric acid (HCl), sulphuric acid (H2SO4) and nitric acid (HNO3).
Among these three acids, sulphuric acid and nitric acid are strong oxidizing agents, which will react with unreactive metals such as copper, lead with oxidation.
Only hydrochloric acid does not have reaction with these metals. Also, for metals which rust (iron) or have stains (oxidized), they are usually reactive metals. So, hydrochloric acid should be used in order not to have other undesirable chemical change between the acid and the metals.資料來源： Myself~~~