Question

Intru-un cristalizator cu 200 g apa se introduc 4,6 g Na metalic. Ce concentratie va avea solutia de NaOH 20% obtinuta?

Answer 1

Na + H2O => NaOH + 1/2 H2
23g Na....18 g H2O....40g NaOH....0,5*2g H2
4,6g Na......x=3,6g.....y=8g...z=0,2g
mdf = 4,6+8+0,2=12,8g
msf = 12,8+3,6+200=216,4g
C=mdf/msf*100=12,8/216,4*100=5,914℅
Nu sunt sigur..