Write down the equations of the reactions: a) Cu → CuO → Cu (OH) 2 → CuCI2 b) Na → Na2O → NaOH → NaCI2

1 chain:

1) 2Cu + O2 = 2CuO (when copper interacts with oxygen, copper oxide is formed);

2) CuO + H2O = Cu (OH) 2 (when copper oxide interacts with water, copper hydroxide is formed);

3) Cu (OH) 2 + 2HCl = CuCl2 + 2H2O (when copper hydroxide interacts with hydrochloric acid, copper chloride and water are formed).

2 chain:

1) 4Na + O2 = 2Na2O (when sodium interacts with oxygen, sodium oxide is formed);

2) Na2O + H2O = 2NaOH (when sodium oxide interacts with water, sodium hydroxide is formed);

3) 2NaOH + BaCl2 = 2NaCl + Ba (OH) 2 (when sodium hydroxide interacts with barium chloride, sodium chloride and barium hydroxide are formed).