Answer to Question #56281 in General Chemistry for Tracy Guido

Question

Ionic equations for the following
4Li(s) + O2(g) → 2Li2O(s)
2Li (s) + 2H2O (l) 2LiOH (aq) +H2 (g)
Ca(s) + 2H20(g) Ca(OH)2(aq) + H2(g)
2Ca(s) + O2 (g) 2CaO (s)
4Al(s) + 3O2(g) → 2Al2O3(s)

Answer 1

4Li(s) + O₂(g) → 2Li₂O(s)

2Li (s) + 2H₂O (l) → 2Li⁺(aq) + 2OH^-(aq) + H₂(g)

Ca(s) + 2H₂O(l) → Ca₂⁺(aq) + 2OH^-(aq) + H₂(g)
*Usually Ca(OH)₂ is almost insoluble in water, so another way is to assume that it's a solid, then the net ionic equation would be different:
Ca(s) + 2H₂O(l) → Ca(OH)₂(s) + H₂(g)

2Ca(s) + O₂(g) → 2CaO(s)

4Al(s) + 3O₂(g) → 2Al₂O₃(s)