when combining metal and water, my book says it can either have a product of a metal oxide or metal hydroxide, but it didn't explain why???
for example:
Na + H2O ---> H2 + NaOH
Fe + H2O ---> H2 + Fe3O4 ( and why does Fe have 3 and O have 4 atoms??)
for example:
Na + H2O ---> H2 + NaOH
Fe + H2O ---> H2 + Fe3O4 ( and why does Fe have 3 and O have 4 atoms??)
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Active metals can displace Hydrogen from water as Standard reduction potentials of most metals are negative. So metals can reduce hydrogen from +1 state to zero state in H2. Now if from water H+ is reduced to H2 then left out ion is OH- so Na+ combines with it to form NaOH
For Iron two states are stable +2 and +3 unlike Na. So, when Fe reduces H+ to H2 it should form Fe(OH)2 + Fe(OH)3. But these hydroxides dehydrate in aerated media to yield an oxide that has both Fe+2 and Fe+3 ions ie Fe3O4. Remember, Fe3O4 is actually FeO.Fe2O3 ie one iron in +2 and 2 irons in +3 state.
For Iron two states are stable +2 and +3 unlike Na. So, when Fe reduces H+ to H2 it should form Fe(OH)2 + Fe(OH)3. But these hydroxides dehydrate in aerated media to yield an oxide that has both Fe+2 and Fe+3 ions ie Fe3O4. Remember, Fe3O4 is actually FeO.Fe2O3 ie one iron in +2 and 2 irons in +3 state.