Cr2O3+H2O= CaO+H2O= Al+H2O= CrO3+H2O= Si+H2O= Zn+H2O= Al2O3+H2O= BaO+H2O= Li+H2O= CO2+H2O= C+H2O= Ni+H2O=

Here are the reactions for each of the compounds with water (H2O), where applicable:

1. Cr2O3 + H2O → This reaction does not typically occur under standard conditions. Chromium(III) oxide is very stable and does not readily react with water.

2. CaO + H2O → Ca(OH)2
   Calcium oxide (lime) reacts with water to form calcium hydroxide (slaked lime).

3. Al + H2O → Under normal conditions, aluminum does not react with water due to an oxide layer. However, at elevated temperatures or in the presence of steam:
   \[\text{2Al + 6H2O} \rightarrow \text{2Al(OH)3 + 3H2}\]

4. CrO3 + H2O → H2CrO4
   Chromium trioxide reacts with water to form chromic acid (H2CrO4).

5. Si + H2O → Silicon does not react with water under normal conditions.

6. Zn + H2O → Zinc reacts slowly with water. More commonly, in the presence of steam:
   \[\text{Zn + H2O (g) → ZnO + H2}\]

7. Al2O3 + H2O → Al(OH)3
   Aluminum oxide reacts with water to form aluminum hydroxide.

8. BaO + H2O → Ba(OH)2
   Barium oxide reacts with water to form barium hydroxide.

9. Li + H2O → Lithium reacts vigorously with water:
   \[\text{2Li + 2H2O → 2LiOH + H2}\]

10. CO2 + H2O → H2CO3
    Carbon dioxide reacts with water to form carbonic acid (H2CO3).

11. C + H2O → Carbon reacts with steam at high temperatures to produce hydrogen gas and carbon monoxide:
    \[\text{C + H2O (g) → CO + H2}\]

12. Ni + H2O → Nickel does not react with water under normal conditions.

Please note that the reactivity and outcomes can depend on specific conditions such as temperature and pressure.