how can painting or adding blocks of zinc prevent rusting on oil rigs?

Answer 1

Zinc breaks down easier than steel and other metals. When a metal is coated or covered with zinc it is called galvanized. The zinc breaks down before the metal does and helps the metal to last longer.

Answer 2

Paint gives a barrier to water, salt, and oxygen.

Zinc is what is called a sacrificial anode. It's more active than the iron in the steel rigs. So the zinc corrodes away preferentially, leaving the iron alone. You have to attach the zinc to the rig by a wire, so electrons can flow as the zinc oxidizes.

Answer 3

Rust is caused by the interaction of metal in the presence of water and oxygen. Basic chemical process where iron will bond with oxygen to form iron oxide. If you put paint on it, you limit the exposure of the metal to oxygen and prevent the process. An alternative is called galvanic protection. This can be done by adding an electrical charge to the metal or alternatively by connecting a cathodic material (zinc) to the metal. The decay of zinc will cause a charge to be induced in the metal and (similar to electric current protection) prevent reaction between metal and oxygen.

Answer 4

Zinc is higher on the metal reactivity series than iron, so the oxidation of zinc in the presence of iron would occur preferentially to oxidation of iron.

Answer 5

Contrary to popular belief, in 2003, Dick Cheney was not dictator of all things oil. In fact, in 2003, Dick Cheney was Vice President or the United States, and president of the Senate, which pretty much means he doesn't get to do much, unless the Senate has a tie score on a vote, then he gets to flip a coin and call it. Dick Cheney used to have substantial stock in a company called Halliburton, which his advisers told him to sell before running on the Bush ticket, in fear of folks saying he had a conflict of interest. So, Cheney sold all his stock, and yet still, he has been accused of a secret association with any oil interests ever since. George Bush used to have substantial stock in a company called Harken Energy, which he sold in 1989 or 1990 in order to buy the Texas Rangers with some other investors. He was later both accused to be a secret insider with Harken, and was accused to insider trading by getting out of Harken, both of which have been proven to be patently false. Dick Cheney is not the secret man behind the curtain for all things evil. Even if he wanted the job, he'd have to yank George Soros out of the seat first.

Answer 6

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