Question

WOW câte puncte !!! Dau coroană !!!!

Answer 1

Din teorie stim ca:

md = masa dizolvatului

ms = masa solutiei = md + m.apa

c% conc. solutie = mdx100/ms

a)

md = 40 g , m.apa = 260 g

=> ms = 40 + 260 = 300 g solutie

=> c% = 40x100/300 = 13,33%

b)

md = 40 g , m.alcool = 360 g

=> ms = 40 + 360 = 400 g solutie

=> c% = 40x100/400 = 10%

c)

ms = 250 g

c% = 35%

=> md = msxc%/100 = 250x35/100

=> md= 87,5 g

d)

- 20% = 20 g iod dizolvat in 100 g solutie

=> md = 20 g , m.solvent = ms - md = 100 - 20 = 80 g alcool

- 25% = 25 g zahar dizolvat in 100 g solutie

=> md = 25 g , m.apa = ms - md = 100 - 25 = 75 g apa

- 40% = 40 g piatra vanata dizolvata in 100 g solutie

=> md = 40 g , m.apa = ms - md = 100 - 40 = 60 g apa