Carry out the transformation CaCO3 = CO2 = H2CO3 = Na2CO3 = BaCO3 = BaCl2

1) When calcium carbonate is heated, carbon dioxide and calcium oxide are obtained:

CaCO3 → CO2 + CaO;

2) When carbon dioxide and water interact, we get carbonic acid:

CO2 + H2O → H2CO3;

3) Carbonic acid reacts with concentrated sodium hydroxide, resulting in sodium carbonate and water:

H2CO3 + 2NaOH → Na2CO3 + 2H2O;

4) In the process of the exchange reaction of sodium carbonate and barium nitrate, we observe the formation of a precipitate of barium carbonate and sodium nitrate:

Na2CO3 + Ba (NO3) 2 → BaCO3 + 2NaNO3;

5) To obtain barium chloride from its carbonate, it is necessary to carry out a reaction between barium carbonate and calcium chloride:

BaCO3 + CaCl2 → BaCl2 + CaCO3.