How do you calculate the number of grams in 0.865 moles?
As written I can you tell you how many particles there are in
The mole is a collective number like a dozen, or a gross, or a score, etc. Admittedly it is a very large collective number.
If I have a mole of stuff, I have
The mole is thus the link between the submicro world of atoms and molecules to the macro world of grams, and kilograms, and litres. This ties in with the notion of equivalence: to have a
It might be worthwhile if you spend some time on these ideas, because even at undergraduate level they seem to be poorly understood. And once you do get it, these sorts of problems are fairly trivial and straightforward.
So back to your problem, we know the number of particles. We don't know the molar mass of the particles. If you specify carbon, hydrogen, oxygen particles, then we can calculate the mass. Capisce?