50.0 g of an oxide of Chromium (Cr) was found to contain 13.28g of potassium (K), 17.68 g of Chromium (Cr) and 19.04 g of oxygen (O). Find the simplest formula...
A chemist cannot relate masses of compounds directly, he/she must always relate molar values.
One must first convert these mass values into mole values by dividing each value by their respective molar masses.
13.28 g K
--------- = ...
Comparing masses of substances is not how a chemist works, a chemist must compare mole ratios, not mass ratios.