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Why should we use platinum wire or loop in flame test, can we use any other material ? Why can't we use glass it something?

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Platinum is chemically inert ("noble") meaning it resists forming oxides or other compounds. This stability is desirable when doing a flame test because it ensures that we only see the spectrum of what we are burning. (Think how much noise we would have in our spectrum if we used a Magnesium wire to hold our sample) Of the chemically inert metals (e.g. Au, Ag, Pd, Pt), Platinum has the highest melting point (2041º C), so it's the most useful for holding in a flame. Glass, on the other hand, melts at a temperatures ~500º C lower than Platinum.

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    $\begingroup$ Of course the melting point of glass depends on the particular glass. Silica melts at 1,710°C, but soda glass melts below 600 °C. $\endgroup$ – MaxW Oct 15 '18 at 18:11
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    $\begingroup$ The kind of glass you're likely to be using also has a lot of additives. You probably don't want those to contaminate your flame test. $\endgroup$ – Zhe Oct 15 '18 at 20:02
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    $\begingroup$ If Mg wire was used, noise in spectrum may be the last problem... $\endgroup$ – Mithoron Oct 15 '18 at 20:38
  • $\begingroup$ I have done flame tests using nichrome wire. It's cheaper (but does add a very slight yellow color to the flame. Platinum is better in that way, but it costs a lot more). $\endgroup$ – AlaskaRon Oct 16 '18 at 1:27

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