👤

In ce raport de masa se amesteca doua solutii de acid sulfuric de concentratie 50% si 10% pentru a prepara o solutie de concentratie 20%?
A. 5:1;
B.1:5;
C.3:1;
D.1:3;
E.2:3;
Ma puteti ajuta? Va multumesc!


Răspuns :

Varianta directă:

50x-20x = 20y - 10y
30x = 10y
=>raportul molar x:y = 10:30 = 1:3 

sauuuu

[tex]x+y[/tex] grame amestec ............ [tex] \frac{50}{100}x + \frac{10}{100}y[/tex]
100 grame amestec ......................... 20

[tex]100(\frac{50}{100}x + \frac{10}{100}y) = 20x + 20y[/tex]
[tex]<=>50x+10y = 20x + 20y[/tex]
[tex]<=> 50x-20x = 20y-10y[/tex]
[tex]<=> 30x = 10y => \frac{x}{y} = \frac{10}{30} = \frac{1}{3}[/tex]