Write down the reaction equations. 1.Si → SiO2 → Na2SiO3 → H2SiO3 → SiO2 → Si

Write down the reaction equations. 1.Si → SiO2 → Na2SiO3 → H2SiO3 → SiO2 → Si 2.Ca → CaO → Ca (OH) 2 → Ca3 (PO4) 2 → CaCl2

1. Reaction of combustion of silicon.

Si + O2 = SiO2.

2. The reaction of silicon oxide and alkali proceeds with the formation of sodium silicate.

SiO2 + 2NaOH = Na2SiO3.

3. The reaction between sodium silicate and hydrochloric acid leads to the formation of silicic acid and sodium chloride.

Na2SiO3 + 2HCl = 2NaCl + H2SiO3.

4.Silicic acid decomposes into silicon oxide and water when heated.

H2SiO3 = SiO2 + H2O.

5.Silicon is reduced from silicon oxide by active metal (magnesium).

SiO2 + 2Mg = Si + 2MgO.

B).

1. Make the equation for the reaction of calcium combustion. As a result, calcium oxide is formed.

2Ca + O2 = 2CaO.

2. Calcium oxide – basic oxide, reacting with water, forms a base – calcium hydroxide.

CaO + H2O = Ca (OH) 2.

3. The reaction between calcium hydroxide and phosphoric acid proceeds with the formation of calcium phosphate and water.

3Ca (OH) 2 + 2H3PO4 = Ca3 (PO4) 2 + 6H2O.

4.Ca3 (PO4) 2 + LiCl = Li3PO4 + CaCl2.