When put a magnesium into steam, magnesium oxide is formed. When you add a potassium into water, potassium displace the hydrogen in water molecule and form potassium hydroxide + hydrogen. Why the hydrogen in the hydroxide ion would not be displaced by potassium? Calcium in group II form hydroxide ion in water too. Why?
2007-12-28 23:00:31 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
If you had excess potassium, you would on paper have the possibility of ending up with K2O. I am not sure if this happens, because the packing of the relatively large K+ round O 2- is not particularly favourable.
Magnesium hydroxide in the presence of excess water is actually more stable than magnesium oxide, but not by much. Magnesium oxide is more accessible from the hydroxide than those of the other elements in Groups 1 and 2 (except in the case of beryllium), because of the small size of the Mg2+ cation.
2007-12-29 01:16:21 · answer #1 · answered by Facts Matter 7 · 0⤊ 0⤋
Check out the REACTIVITY SERIES of metals and find out the reactivities of metals with respect to Hydrogen.
2007-12-29 00:40:26 · answer #2 · answered by Gentle Rain 2 · 0⤊ 0⤋