a) HCl+NaOH ---> NaCl + H2O
C=36,5% HCl
ms= 200g
c=60%
c=md/ms x 100 => md=200x60/100=120g NaOH
M NaOH= 40g/mol
mHCL= 36,5 x 120 /40 = 109,5g HCl
ms=100x109,5/36,5 => ms= 300g solutie HCl
b) MNaCl= 58,5 g/mol
MH20= 18g/mol
M amestec= 58,5+18= 76,5g
76,5g amestec .......... 58,5g NaCl
100g amestec .......................x
X=100 x 78,5/76,5
x= 76,4 % NaCl