Question

va rog frumos ajutați mă

Answer 1

md = 30 g, c% = 20% si c% = mdx100/ms

=> ms = mdx100/c% = 30x100/20 = 150 g sol.

a.

m.apa = 150 g

=> ms.final = ms1 + m.apa = 150 + 150 = 300 g

=> c%2 = mdx100/ms2

=> c%2 = 30x100/300 = 10%

=> c2% = 1/2 c%1 => adevarat

b.

ms.final = ms1 - m.apa evap = 150 - 75 = 75 g sol.

=> c%2 = mdx100/ms2

=> c%2 = 30x100/75 = 40%

=> c2% = 2xc%1 => adevarat

c.

md.final = md + 50 = 30 + 50 = 80 g

ms2 = ms1 + 50 = 150 + 50 = 200 g sol

=> c%2 = md.finalx100/ms2

=> c%2 = 80x100/200 = 40% => adevarat

d.

m.apa din sol. initiala = ms - md = 150 - 30 = 120 g

=> fals