Răspuns:
100gNaOH...............10g NaOH impuritati
800gNaOH................xg NaOH impritati
x=800x10/100=80g impuritati NaOH
MNaOH=23+16+1=40g/mol
MNa2SO4=2x23+32+4x16=142g/mol
2x40g..........................142g
2NaOH + H2SO4 → Na2SO4 + H2O
80g..................................xg
x=80x142/2x40=calculeaza
Explicație: