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
-
an interaction with nitrogen of the air at very low temperatures
-
an interaction with water vapour contained in the humid air
-
a change in the partial pressure of oxygen in the air
-
a change in the crystalline structure of tin
Solution
D.
a change in the crystalline structure of tin
As temperature decrease, white tin (beta-form) changes to grey tin (alpha form)
Alpha -Sn has a much lower density
