An oxide of iron contains `69.94% Fe` and `30.06%O`. Determine its E.F. `(Fe = 55.85, O = 16.0)`

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 an oxide of Iron which has 69.9% Iron and 30.1% dioxygen by mass. [Atomic mass of Fe=56, O=16 ]

An oxide of iron is found to contain 69.9% iron and 30.1% dioxygen (O_(2)) by mass. Calculate its empirical formula.

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

A mineral of iron contains an oxide containing 72.36% iron by mass and has a density of 5.2 g/cc. its unit cell is cubic with edge length of 839 pm. What is the total number of atoms (ions) present in each unit cell ? (Fe -56, O-16)

The earliermethod for determining the molecular weight of proteins was based on chemical analysis. The following composition of proteins were found : Haemoglobin: 0.335% Fe Cytochrome protein: 0.376% Fe Peroxidase enzyme : 0.29% Se If haemoglobin contains 4 atoms of iron, then approximate molecular mass of haemoglobin is (at. mass of Fe = 55.85)