Magnesium powder was fused with amorphous silicon. The alloy was placed in a hydrochloric acid solution.

Magnesium powder was fused with amorphous silicon. The alloy was placed in a hydrochloric acid solution. The gas released during the reaction ignited in air. The product of gas combustion — a solid substance — was fused with sodium hydroxide. Make the equations for the reactions described.

1) Magnesium + silicon => magnesium silicide: 2Mg + Si => Mg2Si;
2) Magnesium silicide + hydrochloric acid => magnesium chloride + monosilane (gas): Mg2Si + 4HCl => 2MgCl2 + SiH4 ↑;
3) Monosilane + oxygen => silicon dioxide + water: SiH4 + 2O2 => SiO2 + 2H2O;
4) Silicon dioxide + sodium hydroxide => sodium metasilicate + water: SiO2 + 2NaOH => Na2SiO3 + H2O.