Answer:
7 moles of Cr
Explanations:
Given that there is 1 mole of he compound Cr7(PO4)3, the 1 mole of the compound is composed of 12moles of oxygen, 3 moles of phosphorous and 7 moles of chromium.
Hence we can conclude that there will be 7 moles of Cr in 1 mole of Cr7(PO4)3