air,water,acid and salt solution....
the ans is air,water and acid...
do u all agree with the ans???
i think is acid and salt solution only
2007-07-30 01:44:40 · 6 answers · asked by red devil 4 in Science & Mathematics ➔ Chemistry
Air and water are necessary for rusting, and acid and salt will increase the rate of rusting if air and water are already present.
So I don't agree with the answer. Look at how fast iron railings (or cars) rust by the sea - salt definitely increases the rate of rusting, as well as any acid.
2007-07-30 01:55:13 · answer #1 · answered by Gervald F 7 · 0⤊ 0⤋
I personally think it'd be all of the above. Water oxides metal to produce rust. Air can be corrosive especially when damp but air takes a long time.
Acid contains the necessary ions to cause a reaction resulting in rust and we all know it's a corrosive substance. Also, rusting is essentially corrosion so one and one you put together makes two.
Salt solution is a solution of water and salt. As said earlier, metal oxidises in water. But I think since salt is a neutral pH substance, it doesn't alter the pH of the general solution, so the rusting would be the same rate as pure water (unless salt crystals rub against the metal to cause greater exposed surface area)
2007-07-30 09:26:01 · answer #2 · answered by Winnie C 3 · 0⤊ 0⤋
Damp Air and acid will increase the rate of rusting.
2007-07-30 09:05:08 · answer #3 · answered by jinu 1 · 0⤊ 0⤋
Rust is made by oxygen chemically combining with iron, so it would be the ones with oxygen, which are air, water, and salt solution.
Most acids actually contain no oxygen, but the ones that do might increase rust.
2007-07-30 08:55:04 · answer #4 · answered by 1337 1 · 0⤊ 2⤋
Air , water and acids increase the rate of rusting
Pure, solid iron oxidizes in water:
Fe (s) >> Fe2+ + 2e-
These electrons will quickly react with the dissociated hydrogen ions and the dissolved O2 in the water :
4e- + 4 H3O+ + O2 >> 6 H2O
Rust is the oxide that is formed by open air oxidation of iron.
The chemical composition of rust is Fe2O2 n H2O and under wet condition FeO(OH)
2007-07-30 08:54:50 · answer #5 · answered by Dr.A 7 · 0⤊ 1⤋
increasing rate of rusting = which one is a catalyst?
air (oxygen): 4Fe + 3O2 -> 2Fe2O3
water: 2Fe + 3H2O -> Fe2O3 + 3H2 (very slowly)
acid: 6Fe + 6HX -> 2FeX3 + 3H2 (faster than water)
base on activity series, salt shouldn't react. it might lower the activation energy. if so, it is the only catalyst.
2007-07-30 09:50:32 · answer #6 · answered by Carborane 6 · 0⤊ 0⤋