Ответ: даноm(Na2O) = 6.2 gm(H2O) = 100 g————————-W(NaOH) -?Na2O+H2O—>2NaOHM(Na2O) = 62 g/moln(Na2O) = m/M = 6.2/62 = 0.1 moln(Na2O) = 2n(NAOH) = 0.1*2 = 0.2 molM(NaOH) = 40 g/molm(NaOH) = n*M = 0.2*40 = 8 gW(NaOH) = 8 / (6.2+100) *100% = 7.54 %ответ 7.54 %