01-24-2009, 04:26 AM
Dennis S wrote:
I ran across this. I thought it was fascinating:
"The disadvantage of deionized water is that it is very corrosive to metal. Since it has no dissolved solids in it, water will seek equalibrium with whatever it contacts. So water with a pH of 7.0 can dissolve metal pipe. Especially yellow metals like copper and brass. It is also very aggressive to mild steel or "black" iron, and forget about glavanized pipe. Piping that resists the effects best is PVC or glass."
Sorry, but no.
What happens with water is that a small number of water molecules dissociate into hydronium and hydroxide ions. There is nothing "magical" about a ph of 7. It is simply a reflection of the fact that there are exactly the same number of hydronium ions as there are hydroxide ions in a sample of water. This is why pure water conducts electricity.
Copper does not react with water under any circumstances. Copper can only displace hydrogen from acid.
Look into something called the "activity series"...