2HCl + Ca(OH)2----> CaCl2 + 2H2O
1mol.......1mol
HCl + NaOH---> NaCl + H2O
X..........2mol
X=2molHCl
1mol.....1mol.........1mol
HCl + NaOH--->NaCl + H2O
X..............Y................4
X=Y=4mol
2mol.........1mol.
2HCl + ZnSO4----> ZnCl2 + 2H2O
x.............2mol
x=4molHCl