Question

Subiectul II va rog, este urgent!!
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Answer 1

S.II:

1.

md = 65g, m.apa = 135g

stim ca ms = md+m.apa = 65+135 = 200g

stim ca c% = mdx100/ms

= 65x100/200 = 32,5%

2.

ms = 500g, c% = 50%

=> md = msxc%/100

= 500x50/100 = 250 g substanta dizolvata

3.

ms1 = 200g, c1% = 25% si c2% = 2c1% = 50%

ms2 = ms1 - m.apa.evaporata = ms1 - a

md = ms1xc1/100 = 200x25/100 = 50g

c2% = mdx100/ms2

=> 50 = 50x100/(200-a)

=> a = 5000/50 = 100 g apa evaporata