What is the chemical formula of Calcium Carbide? What is the difference between Ferric oxide and Ferrous oxide

Question

Then what is Fe3O4?

Answer 1

the formula of calcium carbide is CaC2

iron exhibits double valency.let us see what is double valency.

an element loses electrons from outermost shell to attain stability.but some elements lose electron even from the penultimate shell or the last but one shell.this results in the formation of two types of ions.

for example,take lead
there are both [Pb]2+ [Pb]4+

similarly iron also has two valencies ie [Fe]2+ [Fe]3+

hence it forms two oxides that is ferrous {the one with 2+ charge} and ferric{the one with 3+ charge.}

the formulae are Fe2O3 {ferric and Feo{ferrous}

Answer 2

calcium carbide is CaC2
here carbon is in the oxidation state
(C2)2-
ferrous oxide is FeO Fe is in +2 o.s
ferric oxide is Fe2O3 Fe is in +3 o.s
these two forms Fe3O4 which is a nonstoichiometric compd.

Answer 3

Calcium carbide is CaC2
Ferrous oxides have a valency of 2, and are usually green
Ferric oxides have a valency of 3 and are usually red

Answer 4

since the valency of ferric ion is 3 and oxide ion is 2 the formula is fe2o3

Answer 5

Check these three Wikipedia articles:

Calcium Carbide: http://en.wikipedia.org/wiki/Calcium_carbide

Ferric Oxide (commonly known as rust): http://www.answers.com/topic/iron-iii-oxide (Answers.com article which also includes Wikipedia entry.)

Ferrous Oxide (black powder used in the manufacture of steel): http://www.answers.com/topic/iron-ii-oxide (Answers.com)

Answer 6

CaC2 Fe2O3=ferric ,FeO=ferrous. Generally in industry to avoid confusion with many chemicals we use Fe(II) or Fe(III) to avoid confusion.