Răspuns:
Explicație:
m d H₂SO₄ (1)= c*ms/100= 42*600/100=252 g
m d H₂SO₄ (2) = 20*400/100=80 g
m d H₂SO₄(3)= 5*100/100=5 g
m pur H₂SO₄= md H₂SO₄(4)= 50 g
m d total H₂SO₄= m d H₂SO₄ (1)+m d H₂SO₄ (2)+m d H₂SO₄(3)+m pur H₂SO₄
= 252+80+5+50=387 g
m s total H₂SO₄= 600+400+100+900=2000 g
c final= (m d total/ms total)*100= (387/2000)*100=19,35 => c%=19,35%