Write the reaction equation: Carbon – Carbon dioxide – Sodium carbonate – Carbonic acid – Barium carbonate

1) C + O2 = CO2 (when carbon interacts with oxygen, carbon dioxide is formed);

2) CO2 + Na2O = Na2CO3 (when carbon dioxide interacts with sodium oxide, sodium carbonate is formed);

3) Na2CO3 + 2HCl = 2NaCl + H2CO3 (when sodium carbonate interacts with hydrochloric acid, sodium chloride and carbonic acid are formed);

4) H2CO3 + Ba (OH) 2 = BaCO3 + 2H2O (when carbonic acid interacts with barium hydroxide, barium carbonate and water are formed).