How many sodium atoms are present in #7Na_3PO_4#?

1 Answer
Jun 24, 2016

Answer:

Well, how many sodium atoms in one formula unit of #Na_3PO_4#?

Explanation:

I can count #3# in the one formula unit. In one mole of compound, there are also #3*mol# of sodium.

Now you have quoted #7*Na_3PO_3#, i.e. #7*"formula units"# OR #7*"moles"# of sodium phosphate. And thus #3xx7=??# #"how many sodium atoms or how many moles of sodium atoms?"#