Question

Calculeaza partea de masa de KOH in solutia obtinuta prin amestecarea a 100g solutie de KOH de 10% cu 50g solutie de KOH de 50%

Answer 1

$\frac{c}{100} = \frac{md}{ms}$;
$\frac{20}{100} = \frac{md1}{100}$ => md1=20g;
$\frac{50}{100} = \frac{md2}{50}$ => md2=(50×50)÷100=25g
$\frac{cf}{100} = \frac{md1+md2}{ms1+ms2}$;
$\frac{cf}{100} = \frac{20+25}{100+50} = \frac{45}{150}$ => cf=(45×100)÷150=30%