How many moles of NF3 are in 850.49 grams of nitrogen triflouride

Answer 1

NF3? how many moles of NF3 are in 850.49grams?

molesNF3=mass/molmassNF3

Answer 2

921.4919096 g/mol

does this look to be right?

or 1 grams 850.49 NF3 is equal to 0.00108519672238 mole does this look better?

Answer 3

No, it doesn't look right to me.
molar mass NF3 = 71.00
So 850.49/71.00 = ??
I don't know how you came up with 921 something for a molar mass.