calculate the mass in grams of

Question

Calculate the mass in grams of 3.50 x 10¹² molecules of ammonium tartrate. 

Answer 1

(1) Find the molecular weight (grams/mole) of ammonium tartrate.  Look it up, or add the atomic weights of all the constituent atoms in the chemical formula.

 

(2) Divide the given number of molecules by Avogadro's number (6.02 x 10²³).  That gives the number of moles.

 

(3) Multiply the number of moles by the molecular weight in grams/mole.  That gives the mass in grams.