Tin(IV) oxide, cassiterite, is the main ore of tin. It crystallizes in a rutile-like unit cell with tin(IV) ions taking the place of Ti⁴⁺ ions (Study Question 12.6). (The O²⁻ ions marked x are wholly within the unit cell.)

(a) How many tin(IV) ions and oxide ions are there per unit cell of this oxide?
(b) Is it thermodynamically feasible to transform solid SnO₂ into liquid SnCl₄ by reaction of the oxide with gaseous HCl? What is the equilibrium constant for this reaction at 25°C?

Data given in Question 12.6

Rutile, TiO₂, crystallizes in a structure characteristic of many other ionic compounds. How many formula units of TiO₂ are in the unit cell illustrated here? (The oxide ions marked by an x are wholly within the cell; the others are in the cell faces.)

Transcribed Image Text:

Sn4+ -0²-