Eli5 reversing silver tarnish


Pure silver also gets oxidized . So does heating pure silver can remove the tarnishing and make it white . If so what’s happening .
Also does pure silver turns black when heated

In: 1

You understand that oxidation is when oxygen atoms attach themselves to another atom or molecule, there is typically a transaction involved electrons that make this ‘desirable’ for both compounds.

In the case of silver bars, it’s simply oxygen bonding with silver atoms forming silver rust – Ag2O.

Removing silver rust is achieved via heating – the heat makes the oxygen’s pull off the silver atoms and become molecular oxygen again.

Now *silver tarnish* is something else – this is silver *sulfide.* To remove silver tarnish you need to provide metal atoms appealing to the sulfur than silver. There a few methods but the common DIY method involves aluminum/aluminium foil. The sulfur desires the aluminum more so it leaves the silver behind. Removing the tarnish. There is another ‘electron transaction’ happening here so this type of tarnish removal is comparable to an electronic battery circuit with electrons flowing around between the between the metals when immersed in a liquid solution that allows this to happen.

Finally talking about turning ‘black during heating’ is a tricky thing because often the black is isn’t a chemical reaction, it’s a sooty deposit left behind by the heat source, like wood soot or oily wax soot from a candle. This is just cleanable and not really a chemical reaction with the silver.