Question

2) 250 ml solutie soda caustica cu p=1,437 g/cm cub,c=40% se amesteca cu 200g apa. Care va fii noua concentratie a solutiei?

Answer 1

Vs=250 ml
p=1,437g/cm cub
c=40%
mapa=200g
c2=?

p=$\frac{ms1}{Vs}$
ms1=p*Vs
ms1=1,437*250
ms1=359,25g

md1=$\frac{c*ms1}{100}$=$\frac{40*359,25}{100}$=143,7g
md1=md2
ms2=ms1+mapa
ms2=359,25g+200g
ms2=559,25g

c2=$\frac{md2*100}{ms2}$

c2=$\frac{143,7*100}{559,25}$=25,59%