Write the reaction equations for a series of transformations Sio2-Si-Mg2Si- Sih4-Sio2

1) SiO2 + 2C = Si + 2CO (when silicon dioxide interacts with carbon, silicon and carbon monoxide are formed);

2) Si + 2Mg = Mg2Si (when silicon interacts with magnesium, magnesium silicide is formed);

3) Mg2Si + 4HCl = 2MgCl2 + SiH4 (when magnesium silicide interacts with hydrochloric acid, magnesium chloride and silane are formed);

4) SiH4 + 2O2 = SiO2 + 2H2O (when silane interacts with oxygen, silicon dioxide and water are formed).