question_answer

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 temperatures

C) a change in the partial pressure of oxygen in the air

D) an interaction with water vapour contained in the humid air

Correct Answer: A

Solution :

As temperature decreases, white tin (p-form) changes to grey tin (a-form). \[\alpha -Sn\beta -Sn\] has a much lower density.