Question

The soldiers of Napolean army while at Alps during freezing winter suffered a serious problem as regards to the tin buttons of their uniforms. White metallic tin buttons got converted to grey powder. This transformation is related to ;

• A. A change in the crystalline structure of tin.
• B. An interaction with nitrogen of the air at very low to temperature.
• C. A change in the partial pressure of oxygen in the air.
• D. An interaction with water vapour contained in the humid air.

Answer 1

Answer: (A)

A change in the crystalline structure of tin.

Answer 2

White metallic tin i.e. $\beta$ -Sn changes to another allotrope, the grey tin the $\alpha$ -Sn at low temperature.