Na → Na2O → NaOH →Na2SO4→ NaCl ↓ Na2CO3

Question

Na → Na2O → NaOH →Na2SO4→ NaCl

↓

Na2CO3

Answer 1

4Na + O2= 2Na2O

2Na2O + 2H2O= 4NaOH  и   Na2O +2H2CO3= 2NaCO3 + 2H2O

NaOH + K2SO4 = Na2SO4 + KOH

Na2SO4 + CaCl = NaCl + CaSO4