CaCl2 + Na2CO3 = CaCO3↓ + 2NaCl Ca[2+] + 2Cl[-] + 2Na[+] + CO3[2-]= CaCO3↓ + 2Na[+] + 2Cl[-] Ca[2+] + CO3[2-] = CaCO3↓ HCl + NaOH = NaCL + H2O H[+] + Cl[-] + Na[+] + OH[-] = Na[+] + CL[-] + H2O H[+] + OH[-] = H2O