Identify the type of reactions:
1. CaO+H2O-----Ca(OH) 2
2. CuSO4 + Zn ZnSO4+Cu
3. N2 + 3H2 ----> 2NH3
4. Fe+2HCl---->FeCl2
5. C+O2--->CO2
6.H2SO4 + NH4OH ----- H2O + (NH4)2SO4
7.Mg +Fe2O3 ------ Fe + MgO
In this Ca SO4.1/2 (H2O ) how a molecule of water can be divide into half?