Question

URGENT!!!100 PUNCTE+COROANA!

Answer 1

46 g         m g           md         n moli

2Na   +  2H2O ---> 2NaOH + H2

2x23     2x18             2x40       1

=> m = 36 g apa consumata

m.apa ramasa = 436 - m = 400 g

md = 80 g NaOH

n = 1 mol H2

c% = mdx100/ms

= 80x100/400 = 20% sol NaOH

80 g     md          m        a

NaOH + HCl --> NaCl + H2O

40         36,5      58,5    18

=> md = 73 g HCl

=> ms = mdx100/c%

= 73x100/10 = 730 g sol HCl

m.apa sol HCl = 730-73 = 657 g apa

=> m = 117 g NaCl

a = 36 g apa nou formata

=> m.apa totala = 400+657+36 = 1093 g

c%.finala = 117x100/1093

= 10,71%