Answer:
Triclinic crystal forms. Also known as the rhombohedron system, its shape is three dimensional like a cube, but it has been skewed or inclined to one side making it oblique. All crystal faces are parallel to each other. A rhombohedral crystal has six faces, 12 edges, and 8 vertices.
bascially short answer is 6 faces
Missing in your question the K constant value =2.99X10^-7
The reaction equation:
SOCl2 ⇄ SO2 +Cl2
initial 0.195 0 0
-X +X +X
final (0.195-X) X X
K= [SO2][Cl2]/SOCl2
by substitution
2.99X10^-7 = (X)(X)/(0.195-X)
2.99X10^-7 = X^2 / (0.195-X) by solving this equation
∴X = 0.00024 = 2.4 X10^-4
∴[Cl2] = 2.4X10^-4 m
The crust is the outside layer and also the thinnest.