I am curious to know if bones generally are harder to corrode than human skin in our world and at what rate?

I was thinking to compare how a skeleton would react to corrosion compared to a regular human. Maybe some chemists or the likes had any insight to this. I see many fantasy universes incorporate "acid" as an element but neglect bases and corrosions as a whole.

Bonus question, is it possible to find a list on how different metals react to strong acids and bases. I have heard of the Reactivity series, but not much beyond that, or perhaps I just don't understand how to use it. I should note my level in chemistry is very basic, so I hope anyone can enlighten me.

P.S. I can clarify. Let's say someone were to splash some strong base/acid on a substance made of bone vs. human skin tissue, then which of the two materials would have the best chance to not be "eaten" so to say. I know it is a bit of an open question. I can also rephrase my metal question: If a person was to make an armor suit of any metal of his/her choice which would than be best at not being "eaten" by the acids/bases?


closed as off-topic by SRM, L.Dutch, Erin Thursby, JDługosz May 18 '17 at 6:33

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  • $\begingroup$ Are you asking for the specific alloy of metal or just a type? $\endgroup$ – William C. May 18 '17 at 1:09
  • $\begingroup$ I am asking both for alloys and metals, and reactions with acids/bases to them $\endgroup$ – Andreas Jørgensen May 18 '17 at 1:11
  • $\begingroup$ I don't think that organic compounds corrode. Acids (and bases, etc) burn them: en.wikipedia.org/wiki/Chemical_burn $\endgroup$ – RonJohn May 18 '17 at 1:15
  • $\begingroup$ Allright, lets say they "burn" them the question still remains just with the word burn. (: $\endgroup$ – Andreas Jørgensen May 18 '17 at 1:18
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    $\begingroup$ It's good policy to delay accepting an answer for at least a day so people from every time zone can weigh in. $\endgroup$ – sphennings May 18 '17 at 1:49

Generally, bone is harder to dissolve than skin. Bone is composed of collagen fibres and and inorganic components, primarily hydroxyapatite and other salts of calcium and phosphate. Skin is primarily composed of keratin, collagen, elastin, fat, and cells. Keratin is the tough outer covering of the skin, and it is a protein. Proteins are easily denatured by acids. So the inorganic components of bone make it stronger but also less flexible.The most efficient acid for dissolving a human body would be concentrated sulphiric acid. There's a special case for hydrofluoric acid, however. It's a weak acid made by dissolving hydrogen fluoride in water, and can cause burns at concentrations higher than 50%. Its effects on the skin are mild (irritation, burns) but it's absorbed into the bloodstream on contact, where it dissociates into hydrogen ions and fluoride ions. Fluoride ions form insoluble salts with calcium and cause bone resorption and cardiac arrhythmias. Fluorine has a very high affinity for calcium so it's effective in dissolving bone.

  • $\begingroup$ Thank you. brilliant answer. You sound where enlightened (: would you have any comment regarding the metals? $\endgroup$ – Andreas Jørgensen May 18 '17 at 1:29
  • $\begingroup$ You mentioned knowledge of the reactivity series; that should guide you along pretty well. The metals higher up in the reactivity series are more easily corroded. However, the least reactive metals (copper, mercury, silver, gold) are too soft to make effective armour. Platinum might be used, but its melting point is very high so that would increase costs. Your best bet would be nickel-plated bronze, as nickel is reasonably hard, strongly resistant to corrosion by alkali, and resistant to corrosion by acids as well, and bronze is reasonably hard enough to compensate for nickel's softness. $\endgroup$ – Innocent Immaculate Acan May 18 '17 at 1:54
  • $\begingroup$ @Innocent Immaculate Acan, about platinum, besides the high melting point, the main problem with platinum is the fact that it costs just under $900 to 1,050 US per ounce, so you could outfit around two soldiers, and then just throw away your military budget. $\endgroup$ – Gryphon May 18 '17 at 2:43

I was going to put this in a comment but it was too long. Well if your are talking just corrosion then just google metals that don't oxidize, or rust quickly. Time would just depend on the PH value of the substance vs your coating. Bones don't corrode they dissolve in substances and as it is bones are normally nonreactive to most things over a short period of time but being made up of mostly calcium and other cells just find whats reactive to that. I have no hard answers as there are too many to pick from, so I'm just gunna hit you with some general knowledge.

  • $\begingroup$ thank you for your answer. My understanding was that different metals reacted differently to different kinds of corrosive products. Like metal "X" is good against chemical "Z" but not chemical "W" and metal "Y" is vice versa, or something. I have tried to google this but it did not really help me much thus I turn to stack exchange. I know this is a bit Hollywood, but I remember seeing an alien movie where they could pour this liquid on metal and it would just go right through it! But I guess bones in general are better protected than skin then? $\endgroup$ – Andreas Jørgensen May 18 '17 at 1:25
  • $\begingroup$ Bones are stronger for a reason, skin is a barrier and bone is a structure. An example of a metal that is strong against corrosion would be iridium but especially lead. To my knowledge it is quite difficult to erode lead. $\endgroup$ – William C. May 18 '17 at 1:44

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