Question #88b38

1 Answer
May 15, 2015

The mass of 11.45 mol Arsenic atoms is 857.9 grams.

From the periodic table of the elements, we can see that the atomic weight of Arsenic, As, is 74.92160 amu. We can make a direct conversion to the molar mass of As as 74.92160 g/mol. This gives us two conversion factors for the mass per mole of As:

(74.92160 "g As")/(1 "mol As")74.92160g As1mol As and (1 "mol As")/(74.92160 "g As")1mol As74.92160g As

To convert the given moles of of an element to mass, we multiply the given moles times the conversion factor that cancels moles and leaves grams.

11.45 cancel("mol As")xx(74.92160 "g As")/(1 cancel("mol As"))=857.9 "g As"