Question

Do 02,dm3 15% roztworu soli o gęstości 1,2g/cm3 dodano 60cm3 wody i 4 g soli. Oblicz stężenie procentowe otrzymanego roztworu.

Answer 1

V1 = 0,2dm3 = 200cm3

Cp1 = 15%

d1 = 1,2g/cm3

 

m1 = 1,2 * 200 = 240g

ms1 = 15/100 * 240 = 36g

 

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V2 ( H2O ) = 60cm3

dH2O = 1g/cm3

mH2O = 60g

 

ms2 = 4g

 

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mrc = 240 + 60 + 4 = 304g

msc = 36 + 4 = 40g

 

Cp = 40/304 * 100% = 13,16%

Answer 2

vr=0,2dm3

dr=1,2g/cm3=1200g/dm3

mr=vr*dr

mr1=1200*0,2=240g

Cp1=15%=0,15

ms1=0,15*240=36g

ms2=36g+4g=40g

dH2O=1g/cm3

mH2O=60g

mr2=240g+60g+4g=304g

Cp2=ms2/mr2*100%

Cp2=40g/304g*100%=13,16%