Question

Se amesteca trei solutii de acid cu masele 100 g,200 g respectiv 400 g,avand concentratiile procentuale masice 20%,15%,respectiv 5%.Calculati concentratia procentuala masica a unei solutiei rezultate

Answer 1

ms1 = 100 g
ms2 = 200 g
ms3 = 400 g
c1 = 20 %
c2 = 15 %
c3 = 5 %
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c% = ?

c% = md / ms * 100
c / 100 = md / ms
md1 = (ms1 * c1) / 100
md1 = (100 * 20 ) / 100
md1 = 20 g
 md2 = (200 * 15 ) /100
md2 = 30 g
md3 = (400*5 ) / 100
md3 = 20 g

ms = ms1 + ms2 + ms3
ms = 100 + 200 + 400
ms = 700 g

md = md1 + md2 + md3
md = 20 + 30 + 20
md = 70 g

c% = md / ms * 100
c% = ( 70 * 100 ) / 700
c% = 10 %