A 2.241 g sample of zinc reacts with oxygen to form 2.789 g of the metal oxide.

Question

calculate the empirical formula for oxide

Answer 1

grams of Zn = 2.241 g

grams O = 2.789 g - 2.241 g = 0.548 g

moles Zn = 2.241 g x 1 mol Zn/65.39 g = 0.03427 moles Zn

moles O = 0.548 g x 1 mol O/16 g = 0.03425 moles O

Note that mole ratio of Zn to O is 1:1 , i.e. 0.0343 moles Zn and 0.0343 moles O

Empirical formula = ZnO