Write down the reaction equations: a) sodium – sodium peroxide – sodium oxide – sodium hydroxide – sodium sulfate.

Write down the reaction equations: a) sodium – sodium peroxide – sodium oxide – sodium hydroxide – sodium sulfate. b) iron – iron chloride (||) – iron chloride (|||) – iron hydroxide (|||) – iron oxide (|||) – iron. c) calcium calcium oxide-calcium hydroxide – calcium carbonate-calcium bicarbonate – calcium carbonate-calcium chloride-calcium.

A)

1. Sodium, unlike other alkali metals, forms peroxide with oxygen.

2Na + O2 + Na2O2.

2. 2 Na + Na2O2 = 2 Na2O.

3. Na2O + H2O = 2NaOH.

4.2NaOH + H2SO4 = Na2 SO4 + 2H2O.

B)

1.Fe + 2HCl = FeCl2 + H2.

2.2FeCl2 + Cl2 = 2FeCl3.

3. FeCl3 +3 NaOH = Fe (OH) 3 + 3NaCl.

4.2Fe (OH) 3 = Fe2O3 + 3H2O.

5. Fe2O3 + 3H2 = 2Fe + 3H2O.

С)

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

CaO + H2O = Ca (OH) 2.

2. Alkalis react with acidic oxides to form salts.

Ca (OH) 2 + CO2 = CaCO3 + H2O.

3. When carbon dioxide is passed through a solution of calcium carbonate, an acidic salt is formed – calcium bicarbonate.

CaCO3 + H2O + CO2 = Ca (HCO3) 2.

4. Calcium hydrogen carbonate when heated decomposes into calcium carbonate, carbon dioxide and water.

Ca (HCO3) 2 = CaCO3 + H2O + CO2.

5. We obtain calcium chloride by reacting calcium carbonate with hydrochloric acid.

CaCO3 + 2HCl = CaCl2 + H2O + CO2.

6.Calcium – an active alkali metal, can be obtained by electrolysis (passing an electric current) of its salt melt. In this case, calcium chloride.

CaCl2 (melt) electrolysis Ca + Cl2.