Question

peste 300g de solutie de sare de concentratie 10% se adauga 700g de solutie de sare de concentratie 20%. Concentratia finala este: *
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Answer 1

Răspuns:

Explicație:

ms1=300g sol.

c1=10%

ms2=700g sol.

c2=20%

c3=?

md1= c1 .ms1 : 100

md1= 10 . 300 : 100= 30g sare

md2= c2 .ms2 : 100

md2= 20 .700: 100=140g sare

md3= md1 + md2

md3= 30 + 140= 170g sare

ms3= ms1 + ms2

ms3= 300 + 700=1000g sol.

c3= md3 .100 : ms3

c3= 170 .100 : 1000= 17 %

Answer 2

Răspuns:

ms1=300g

C1=10%

ms2=700g

C2=20%

C3=?

md1= C1xms1 / 100

md1= 10x300 / 100= 30g

md2= c2 xms2 / 100

md2= 20x700/100=140g

md3= md1 + md2 = 30 + 140= 170g

ms3= ms1 + ms2= 300 + 700=1000g

C3= md3 x100 / ms3 = 170x100 / 1000= 17 %

Explicație: