m(H2O) = mраствора - mвещества = 300-10 = 290 г
Wвещества = mвещества/mраствора = 10/300=0,03 = 3%
5/6-3/10):(3/10+2/15)=(25/30-9/30)/(9/30+4/30)=16/30 :13/30=16/30*30/13=16/13
Удачи :-)
Mr(H3PO4) = 1 · 3 + 31 + 16 · 4 = 98
Mr(CuO) = 64 + 16 = 80
Mr(Cl2) = 35,5 · 2 = 71
Mr(CH4) = 12 + 1 · 4 = 16
Mr(NaOH) = 23 + 16 + 1 = 40
Mr(F2) = 19 · 2 = 38
Mr(H2O) = 1 · 2 + 16 = 18
N( H2SO4) = m(H2SO4) / M(H2SO4) =196/98 = 2моль