Question

Calculate the percentage of potassium and O in:

potassium oxide, K₂O

Percentage of potassium: = ________ %

Percentage of O: = _______ %

HELP. I HAVE NO IDEA HOW TO APPROACH THIS.

Answer 1

Element	Symbol	Atomic mass	Atoms	Mass percentage
Oxygen	O	15.9994	1	16.985 %
Potassium	K	39.0983	2	83.015 %

Calculation:

Step 1:- Molecular weight of K₂O = 94.2

Step 2:- Mass of an atom of "K" = 39.0983

Two "K" = 78.1966

Step 3 :- Mass of an atom of "O" = 15.9994

Step 4:- Percentage of "Potassium" in K₂O = [ (Mass of two "K") / (Mass of K₂O) ] 100

= [ (78.1966) / (94.2) ] 100

= 83.011253 %

Step 5:- Percentage of "Oxygen" in K₂O = [ (Mass of One "O") / (Mass of K₂O) ] 100

= [ (15.9994) / (94.2) ] 100

= 16.985 %