Question

Dau coroana! 49. Calculati compozitia procentuala a unei solutii, obtinuta prin amestecarea a 20g solutie, de concentratie 16%, ce contine zahar, cu 30 g solutie, de concentratie 18%, care contine sare.

Answer 1

ms1=20g
c1=16%
ms2=30g
c2=18%
$c1 = \frac{md1}{ms1} \times 100$
$md1 = \frac{c1 \times ms1}{100} \times 100$
$md1 = \frac{16 \times 20}{100 } = 3.2 \: g$
$c2 = \frac{md2}{ms2} \times 100$
$md2 = \frac{c2 \times ms2}{100}$
$md2 = \frac{18 \times 30}{100} = 5.4 \: g$
md=md1+md2=3,2+5,4=8,6 g
ms=ms1+ms2=20+30=50 g
$c = \frac{md}{ms} \times 100$
$c= \frac{8.6}{50} \times 100 = 17.2\%$