# Question: a11535 2 determine the density of the garnet endmember pyrope...

###### Question details

A=11.535

2. Determine the density of the garnet endmember pyrope (Mg3Al2Si3O12) using the unit cell dimensions given above.

(a) Determine the unit cell volume in Å3.

(b) Each unit cell of pyrope contains 8 formula units of Mg3Al2Si3O12. Remembering that 1 mole contains Avogadro's number of formula units, how many unit cells make up one mole of pyrope?

(c) Calculate the volume, in Å3, of 1 mole of pyrope.

(d) Convert the answer from Å3 to cm3. Be careful with your unit
conversions!

(e) Calculate the mass in grams of 1 mole of pyrope by summing the atomic masses of its elemental components. You will need to use a periodic table in order to do this.

(f) Calculate the density (in g/cm3) of pyrope from the volume you calculated in (d) and the mass you calculated in (e). Once you have done this, perform a “reality check” on your answer. Does it make sense if you compare it to the range of Specific Gravity known for garnet? If not, then you have done something wrong. Go back and check your unit conversions.