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I had a test this morning which had the following question:

What is the most common oxidation state for gold?
(a) +1 (b) -1 (c) +2 (d) +3

Since the electronic configuration of $\ce{Au}$ is $\ce{[Xe] 4f^{14} 5d^10 6s^1}$. After removing the $\ce{6s^1}$ electron and gaining $+1$ charge, $\ce{Au}$ should have noble gas configuration and hence this should be the most stable configuration. So the answer has to be +1. Could someone verify my reasoning?

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    $\begingroup$ The most important (natural as well as anthropogenic) oxidation state of gold is actually zero. Apparently, the question refers to the oxidation state of gold in its compounds. $\endgroup$
    – user7951
    Commented May 8, 2016 at 9:10
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    $\begingroup$ Gold is present in $+2$ oxidation state in this complex: $\ce{[Au2Cl2\{μ-(CH2)2PPh2\}2]}$. The +2 oxidation state will stable in dimeric form. $\endgroup$ Commented Dec 13, 2017 at 6:58

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It's not obvious, but common oxidation state for gold is +3. It caused by destabilization of the $5d^{10}$ orbital. Detailed explanation you can find in The Chemistry of Gold, in Chapter 1.1.3.

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  • $\begingroup$ I just checked Wikipedia, it read "Au(I), referred to as the aurous ion, is the most common oxidation state...". I links it to the following study: pubs.acs.org/doi/abs/10.1021/cr980431o $\endgroup$ Commented May 8, 2016 at 13:31
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    $\begingroup$ @Abhishek Mhatre Well, it says in Wiki "Au(I), [...] is the most common oxidation state with soft ligands such as thioethers, thiolates, and tertiary phosphines." And 2 sentences after: "Au(III) (auric) is a common oxidation state, [...]". For example, salts of Au(I) (except insoluble (AuI) or extremle stable $[Au(CN)_{2}]^{-}$) disproportionate in water: $3Au^{+} = 2Au + Au^{3+}$. $\endgroup$ Commented May 8, 2016 at 14:32
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Oxidation is nothing but an atom loosing electrons in chemical compound. Oxidation state works as an indicator and sometime it could be negative or positive or Zero.
Most common Oxidation states of Gold Include +1 (gold(I) and +3 (gold(III)

If you want to know the Less common oxidation states of gold then it includes −1, +2, and +5.

You can know more about gold by exploring its Properties!

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