Question

5. Kyanite (ALSIO5) in a blue colored mineral found in metamorphic rocks What

perfect composition by mass of Aluminum (AI) in Al2SIO5
A. 167%
B. 20,0%
C. 25,0%
D. 33,3%

Answer 1

Answer: 33,3% Al by mass

Step-by-step explanation:

Question's formatting is a little unclear. I'm assuming it's asking for the "percent" composition by mass of Aluminum in Al2SiO5.

Suppose we have 100g of Al2SiO5 to make the calculations easier.

100 g Al2SiO5

x 1 mol Al2SiO5 / (162,05 g Al2SiO5)

x 1 mol Al2 / (1 mol Al2SiO5)

x 2 mol Al / (1 mol Al2)

x 26,98 g Al / (1 mol Al)

------------------------------------

33.30 g Al

Therefore, 33.30 g / 100 g = 33,3% Al by mass