why can heating with carbon not be used to extract aluminium from aluminium ores?
- lenpol7Lv 71 month ago
Because Aluminium is MORE reactive than carbon.Therefore Carbon cannot reduce aluminium oxide to aluminium, because the aluminium will immediately react (with oxygen/air) to reform the oxide.
There is a list of the reactivity of metals. Those above carbon in the reactivity series cannot be reduced by carbon, e.g. Sodium, Potassium, Magnesium, Aluminium. Those below carbon in the reactivity series can be reduced by carbon, e.g. Iron, Copper, Silver.
Those above carbon in the reactivity series, historically, could not be isolated. It was only with the invention of electrolysis, by Michael Faraday, ~ 1850, when the move reactive metals could be isolated. Sodium only existed as Soda Ash , sodium's salt. Similarly, potassium only existed as potash, potassium' salt. However, Gold is so unreactive, that it is found 'native', that is a the metal.