Question

how is 3Fe +4H2O = Fe3O4 +4H2 as valency of fe is not 3 and O2 is not 4​

Answer 1

Here is your answer :

Fe-Iron has a variable valency

${fe}^{2 + } and {fe}^{3 + }$

and,

3Fe +4H2O = Fe3O4 +4H2

Here it is given 4H2O that's why the above equation is correct.

Hop e it helps you.

Plzz MARK AS BRAINLIEST

Answer 2

Answer:

in the above equation 3Fe and Fe₃ have a valency of 8+ (thats because in both the cases there are three atoms with valencies 2+, 3+, 3+ so total is 8+)...and O having a valency of 2- means that O₄ will have a valency of 8+

Fe₃⁸⁺O₄⁸⁻

8 plus and 8 minus get cancelled and the compound becomes stable

:)hope u understood