Write the equations of chemical reactions with which you can get calcium from limestone.

1. Obtaining calcium in three stages:

The decomposition reaction of limestone when heated:

CaCO3 = CaO + CO2.

Interaction of oxide with acid:

CaO + 2HCI = CaCI2 + H2O.

Reaction of chloride with magnesium at 860-1000 ° C:

CaCl2 + Mg = Ca + MgCl2.

2. Receiving in two stages:

CaCO3 = CaO + CO2.

Reduction reaction with aluminum at t = 1200 ° C:

3CaO + 2Al = Ca + Al2O3.

3. Obtaining calcium from chloride:

CaCO3 + 2HCI = CaCI2 + H2O + CO2.

Recovery reaction at t = 600-700 ° C:

3CaCI2 + 2Al = 3Ca + 2AlCI3.