Question

4,6g de sodiu metalic se introduce in 200g apa. Determinati partea de masa a sari dizolvate​

Answer 1

MNa=23g/mol

MH2O =2×1+16=18g/mol

MNaOH=23+16+1=40g/mol

2×23g....2×18g.... 2×40g

2Na +2 H20 => 2NaOH + H2

4,6g ........xg................yg

x=4,6 xx18 /2×23=3,6 g H2O

y=4,6 x80 /46=8g NaOH

200g - 3,6=196,4 g apa in exces

ms=md +mapa

ms=8 + 196,4=204,4 g

C= mdx100/ms

C=8 . 100 : 204,4=3,91 %