Determine the empirical formula `(EF)` of the oxide of chomium containing `68.4% Cr` by mass.

Determine the empirical formula of an oxide of iron which contains 69.9% iron and 30.1% oxygen by mass.

Determine the empirical formula of an oxide of iron which has 69.9% iron and 30.1% oxygen by mass.

Determine the empirical formula of a compound containing Nitrogen = 87.5% and Hydrogen = 12.5%. If the molecular mass is 32. Find its molecular formula.

The atomic mass of a metal M is 56, then the empirical formulae of its oxide containing 70% metal

Determine the empirical formula of a compound containing K=24.75%, Mn =34.77% and rest is oxygen.

Determine the empirical formula of an oxide of iron which has 69.9% iron and 30.1% oxygen by mass. (Atomic mass : Fe = 55.85 amu, O = 16.00 amu).

Determine the empirical formula of a compound containing 47.9% potassium, 5.5% beryllium and 46.6% fluorine by mass. (Atomic weight of Be=9, F = 19, K = 39).

Determine the empirical formula of an oxide of iron, which has 69.9% iron and 30.1% dioxygen by mass.