| MadSci Network: Chemistry |
Rafael and Fred, The answer to your question are acids or bases more corrosive is really not simple. It all depends on what the acid or base is and what it is attacking. There are certain acids which will quickly eat through glass (hydrofluoric) and bases which will do the same (Hydroxides). Similiarly nitric acid will dissolve copper as quickly as concentrated ammonia. The best way to attack this question, from a 6th grade level and for a school project, is to answer the question by saying they are both the same depending on the material being corroded.
This experiment may be useful to show that they are both as corrosive as each other and it all depends on the material being attacked. you will need 20 plastic containers:
Lemon juice + copper nail Lemon juice + stainless steel nail Lemon juice + galvanised (zinc coated) nail Lemon juice + Al foil, white vinegar + copper nail white vinegar + stainless steel nail white vinegar + galvanised (zinc coated) nail white vinegar + Al foil, drain cleaner + copper nail drain cleaner + stainless steel nail drain cleaner + galvanised (zinc coated) nail drain cleaner + Al foil, laundry bleach + copper nail laundry bleach + stainless steel nail laundry bleach + galvanised (zinc coated) nail laundry bleach + Al foil, water + copper nail water + stainless steel nail water + galvanised (zinc coated) nail water + Al foil,What you will see is the copper and galvanised nails start to dissolve in the lemon juice and vinegar containers, and the Al foil dissolve in the drain cleaner and bleach solutions. Nothing should happen in the water. If you then place a copper nail and a galvanised nail in a container with white vinegar you will see something strange occur, one will coat the other, this is not corrosion but electrochemical reaction. This is why you have to keep the nails separate!
Another good experiment is to get 2 raw eggs and place 1 in vinegar, and another in bleach. After a couple of days the egg in vinegar will become translucent as the shell is slowly dissolved, the egg in bleach is unaffected. This illustrates that even though bleach dissolves Aluminium it won't attack the eggshell and this underlines the point that "corrosiveness" depends on the material being corroded.
Hope this answer helps in some way
Dr. Jase
Try the links in the MadSci Library for more information on Chemistry.