posted by Kong on .
i know that metal placed in more acidic solution will produce rust faster.but why metal placed near the sea shore will easily have rust?the wind with moisture which contains salt solution,right?
yup. For a piece of metal to rust fast, you need oxygen, water, and salt.
Rusting occurs much more rapidly in moist conditions as compared to a dry environment such as a desert. Other factors like salt, O2 concentration also affect the rate of corrosion. The presence of salt enhances the rusting of metals because the dissolved salt increases the conductivity of the aqueous solution formed at the surface of the metal and enhances the rate of electrochemical corrosion. This is one reason why iron or steel corrode much more quickly when exposed to moist salty air near the ocean.
thx for your teaching first.however ,i have a problem.When i put the metal in the test tube with sodium chloride solution,it rust slower than the one i put in distilled water with air,why?