Given the formula Ca[3](PO[4])[2]-- Calcium phosphate, if you had 2.00 moles, how many moles of oxygen atoms would you have?
I attempted and got an unsure answer of 16.0
OK, I suck at this, but I know that if the TOTAL moles of the formula is 2... you can't have 16 as one part. 2 < 16.
Find the molar mass of the formula, find the percentage of oxygen, divide by 100, multiply by the total molar mass, & (if there's 2 moles) multiply by 2.
COULD be wrong but based on your problem, I think I'm right. Jiskha?