HNO3 + KOH = KNO3 + H2O
H[+] + NO3[-] + K[+] + OH[-] = K[+] + NO3[-] + H2O
H[+]+ OH[-] = H2O
FeSO4 + 2KOH = Fe(OH)2↓ + K2SO4
Fe[2+] + SO4[2-] + 2K[+] + 2OH[-] = Fe(OH)2↓ + 2K[+] + SO4[2-]
Fe[2+] + 2OH[-] = Fe(OH)2↓
Na2CO3 + 2HNO3 = 2NaNO3 + CO2↑ + H2O
2Na[+] + CO3[2-] + 2H[+] + 2NO3[-] = 2Na[+] + 2NO3[-] + CO2↑ + H2O
2H[+] + CO3[2-] = CO2↑ + H2O