Ответ Автор - MMMAAA97 2Na+2H2O=2NaOH+H2n(Na)=n(NaOH)=4.6/23=0.2m(NaOH)=0.2*40=8m(p)=4.6+150-0.2=154.4w=8/154.4*100%=5.18%