Question: feo is non stoichiometric and has approximate composition fe0.95o?
Answer: The reason why analysis shows that FeO has a non - stoichiometric composition with formula Fe0. 950 is that : The non - stoichiometry reflects the ease of oxidation of Fe^²⁺ to Fe^³⁺ effectively replacing a small portion of Fe^²⁺ with two thirds their number of Fe^³⁺ . 3Fe^²⁺ = 2Fe^³⁺ to maintain electrical neutrality.