Răspuns:
M,NaOH= 40g/mol
prima solutie contine
c,m= n(niu)/V---> n= 1mol/lx0,200l=0,2mol NaOH
solutia finala contine, in plus
n=m/M= 4g/40g/mol=0,1molNaOH adaugat
DECI,in total 0,3mol NaOH in 600ml solutie
c,m= n/V= 0,3mol/0,6 l= 0,5mol/l=0,5M
Explicație: