help me with this...
For each of the chemical reactions below, complete and balance the reactions:
19. HI + Ca(OH)2 →
20. H2SO4 + NaOH →
21. HNO3 + Mg(OH)2 →
22. H2SO4 + Al(OH)3 →
19. 2HI + Ca(OH)2 → CaI2 + 2H2O
20. H2SO4 + 2NaOH → Na2SO4 + 2H2O
21. 2HNO3 + Mg(OH)2 → Mg(NO3)2 + 2H2O
22. 3H2SO4 + 2Al(OH)3 → Al2(SO4)3 + 6H2O