Question

Se amesteca 400 g solutie de soda caustica de concentratie 20% cu 600 g solutie de soda caustica de concentratie 30%. Ce concentratie procentuala are solutia obtinuta?

Answer 1

Se da
ms1=400 g, c1=20%
ms2=600g, c2=30%

Se cere
ct(total)=?

Formula: c=(md*100)/ms;
Derivata formulei: md=(c*ms)/100; (pentru a afla masa de substanta)

md1=(c1*ms1)/100=(20*400)/100=8000/100=80 g
md2=(c2*ms2)/100=(30*600)/100=18000/100=180 g

ct=[(md1+md2)*100]/(ms1+ms2)
ct=(80+160)*100/(400+600)
ct=260*100/1000=26000/1000=26
ct=26%