Question

Subiectul D , ex 4 , va rog !

Answer 1

200 ml HCL, C = 20%;  d=1,1 g/ml
200 ml HCL, C = 30%
100ml H2O   ;   d = 1g/ml

formula densitatii:
d = ms/Vs => (necunoscuta e masa) ms = d * Vs => ms = 1.1 * 200 => ms= 220 g HCL 

d = mH2O/VH2O => m = 100 g H2O

C = md/ms * 100 =>
(1) md = C * ms/100 => 20*220/100 => 44 g HCL
(2) md = C * ms/100=> 30 * 220/100 => 60g HCL

md ( TOTAL) = 44+60 = 104g HCL
ms (TOTAL) = 520 g HCL

C = md * 100/ms => 104*100/520 => C = 20%