Răspuns:
Explicație:
NaOH + HCl = NaCl + H2O
80*36,5/100 = 29,2 g HCl
M HCl = 36,5 g/mol
29,2 : 36,5 = 0,8 mol HCl
1 mol HCl...........1 mol NaOH
0,8 mol HCl.............0,8 mol NaOH
M NaOH = 40 g/mol
0,8*40 = 32 g NaOH
150 g solutie..................32 g NaOH
100 g solutie.......................x
x = 100*32/150 = 21,3%