How do we determine if some metal will undergo passivation under suitable environment?

The passivity of certain metal fall in order:
$\ce{Ti->Al->Cr->Be->Mo->Mg->Ni->Co->Fe->Mn->Zn->Cd->Sn->Pb->Cu}$


Can we predict the order of passivation theoretically? 




There is not much we can do. It is certainly not a property that is explained by a rigorously established single measurable parameter like oxidation potential. Passivation is a delicate interplay of multiple factors, some of which are not even related to the metal itself (remember, a metal may be passive in some environments, but not in the others).


However some trends can be observed. Surely, having a hard, high-melting, and chemically inert oxide does help a lot.


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One of the standard tools for illustrating the tendency to passivation shown by a material is the [Ellingham diagram](https://en.wikipedia.org/wiki/Ellingham_diagram):



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> An Ellingham diagram is a graph showing the temperature dependence of the stability for compounds. This analysis is usually used to evaluate the ease of reduction of metal oxides and sulphides.
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Thermodynamically, the stability of the passivating oxide on the surface of the metal is directly related to the Gibbs free energy change of the oxide formation reaction:



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> The Gibbs free energy $\left(\Delta G\right)$ of a reaction is a measure of the thermodynamic driving force that makes a reaction occur. A negative value for $\Delta G$ indicates that a reaction can proceed spontaneously without external inputs, while a positive value indicates that it will not. ... An Ellingham diagram is a plot of $\Delta G$ versus temperature. ([source PDF](http://web.mit.edu/2.813/www/readings/Ellingham_diagrams.pdf))
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(A detailed Ellingham diagram and a more detailed description of the diagram and its construction can be found at the source link of the above quote.)


In any practical situation, some or all of the ideal assumptions made in generating an Ellingham diagram may or may not apply, but it at least provides a (semi-)quantitative means for arguing relative tendencies to passivation. In particular, as noted by Ivan Neretin, such diagrams don't consider effects of any electrochemical couples that may be active. For that, one would want to cross-reference the appropriate [Pourbaix diagrams](https://en.wikipedia.org/wiki/Pourbaix_diagram) (though, these also suffer from some of the same kinds of idealized assumptions as the Ellingham diagrams).


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