-ecuatia reactiei
1 mol 1mol 2mol
Na2O + H2O-----> 2NaOH
62g.............18g..........2x40g
3,9g............1,132g......5,03g M,Na2o= (2x23gNa+16gO)/m0l= 62g/mol
M,NaOH= (23gNa+1gH+16gO)/mol=40g/mol
c/100= md/ms, unde ms= md+m,apa
md= 5,o3gNa0H
m,apa= 50- 1,132= 48,87; ms= 5,03+48,87
c= 5,03x100/ 53,9-------------------------. calculeaza !!!