Question

Carbon reduction process is not commercially applicable for which of the following set of oxides to extract the respective metal?
I) $ZnO$
II) $Fe_2O_3$
III)$Al_2O_3$
IV)$SnO_2$
V)$MgO$

$A) ZnO,F{e_2}{O_3},Sn{O_2}$
$B) ZnO,Sn{O_2},MgO$
$C) MgO,A{l_2}{O_3}$
$D) MgO,Sn{O_2},A{l_2}{O_3}$

Answer 1

Magnesium and Aluminium are highly reactive metals, the metals which are placed at top most metal activity series and high electropositive metals. Highly electropositive metals easily lose electrons.

Complete step by step answer:
Carbon reduction is done for the only low electropositive elements.
First option is Zinc oxide, Ferric oxide and stannous oxide. In this option the metals are Zinc, Iron and Stannum or Tin. These metals in the activity series of metals placed down, so these metals are considered as medium active metals, so the electro positivity is low. So these oxides are reduced by using Carbon as a reducing agent.
Second option is Zinc oxide, stannous oxide and Magnesium Oxide.
The metals are zinc, Stannum or Tin and Magnesium. The Zinc and Tin is placed in the middle of the activity series so the oxides can be reduced and extracted from the crude metal. But Magnesium is highly reactive metal and placed at top in the activity series, so this magnesium is highly electropositive so cannot be reduced by using Carbon as a reducing agent.
Third option is Magnesium Oxide and Aluminium oxide
Magnesium and Aluminium are the metals of highly reactivity and placed at the top of metal activity series. These two metals are highly electropositive. So these two metals cannot be reduced by carbon as a reducing agent.
Fourth option is Magnesium oxide, stannous oxide and Aluminium oxide
In this option only Tin is low electropositive, so Tin oxide is reduced to Tin by using Carbon as a reducing agent.

Note:
Highly electropositive metals which lose electrons very easily.so highly electropositive elements easily lose electrons, so carbon cannot reduce highly electropositive metals.