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 power. The transformation is related to :

Aluminium chloride exists as dimer, Al₂Cl₆ in solid state as well as in solution of non-polar solvents such as benzene. When dissolved in water, it gives :

Glass is a :

What may be expected to happen when phosphine gas is mixed with chlorine gas?