Question

Ce concetratie in procente de masa va avea solutia obtinuta prin adaugarea a 20 g soda caustica peste 400 g solutie de soda caustica de concentratie 10 %

Answer 1

ms1 = 400 g , c%1 = 10% , c% = mdx100/ms

md1 = ms1xc%1/100 = 400×10/100 = 40 g

md.final = 40 + 20 = 48 g

ms.final = ms1 + 20 = 400 + 40 = 440 g

=> c%final = md.final×100/ms.final

c%final = 48×100/440 = 10,9%