Question

Afla cantitatea de apa necesara
a) obtinerii a 400g solutie CuSO4 de concentratie 60 %
b ) prepararii a 800 L saramura 30% si ρ=1,02 g / cm 3
c) obtinerii a 1, 6 kg solutie NaOH 20 % din sodiu metalic

Answer 1

ms=md + m apa=>m apa=ms-md
c%=(md/ms)*100=>md=(c* ms)/100
a)md=(400*60)/100=>md=240 g
m apa=400-240=160 g apa
b)cM=(c*ro*10)/masa molara=>cM=(30*1,02*10)/58,5=5,23077 moli/litru
cM=md/(masa molara*volum)=>md=cM*masa molara*volum
=>md=5,23077*800*58,5=>md=244,8 kg saramura
ms=(md/ms)*100=(244,8/30)*100=>ms=816kg solutie
m apa = 816 - 244,8=517,2 kg apa
c)md=(1,6*20)/100=0,32 kg
m apa=ms-md=1,6 - 0,32=1,28 kg apa