Question

prin adaugarea unei cantitati de soda caustica peste 50 g solutie de concentratie 20% se obtine o noua solutie de concentratie 23%. Ce masa de soda caustica s a folosit


va rog cat mai repede​

Answer 1

ms1 = 50g , c1% = 20%

ms2 = ? , c2% = 23%

stim ca c% = mdx100/ms

=> md1 = msxc1/100

= 50x20/100 = 10 g soda

md2 = md1 + a, a = masa de soda adaugata

=> ms2 = ms1 + a

=>

c2% = md2x100/ms2

=>

23 = 100(md1+a)/(ms1+a)

=> 50+a = 4,35(10+a)

=> a = 2 g soda adaugata