How many moles of P2O5 contain 3.68*1025 phosphorus atom? The

molar mass of P2O5 is 283.89 g/mol.

4 answers

3.68*10^25 / 6.023*10^26 = 0.061 moles
so 0.061/2 = 0.0305 moles of P2O5 will have that many P atoms
Is that 6.023*10^26 a typo meant to be 6.023*10^23?
yes, it was.
dunno what I was thinking ...

I'm sure @moly can make the adjustment ...
Sometimes the fingers have a mind of their own and they don't go where we tell them to go.