A 19.15 g sample of a compound contains 6.11 g of potassium, K , 5.54 g of chlorine, Cl , and oxygen, O . Calculate the empirical formula. Insert subscripts as needed.

Question

A  sample of a compound contains     and oxygen,  Calculate the empirical formula.

Insert subscripts as needed.

Answer 1

First, we can find the mass of oxygen as follows:

19.15 g - 6.11 g - 5.54 g = 7.5 g of Oxygen

Next we can find the moles of each element:

moles K = 6.11 g x 1 mol/39.1 g = 0.156 moles K

moles Cl = 5.54 g x 1 mol/35.5 g = 0.156 moles Cl

moles O = 7.5 g x 1 mol/16 g = 0.469 moles O

Finally, we convert all moles to whole numbers by dividing all by the lowest value of 0.156:

moles K = 0.156/0.156 = 1

moles Cl = 0.156/0.156 = 1

moles O = 0.469/0.156 = 3

Empirical formula = KClO₃