Question

clasa a 8 a va roggg va implor

Answer 1

Răspuns:

Explicație:

300g sol. NaOH ,c=20%

react. cu o sol. HCl , c=30%

a.   moli HCl cons.

b.    ms HCl

c.    moli sare rezult.

md NaOH= c . ms : 100

md= 20 . 300 : 100= 60g NaOH

60g          xg           yg

Na OH + HCl   =  NaCl  + H2O

40g       36,5g    58,5g

a.

x= 60 . 36,5 : 40 =54,75 g HCl-----> md sol. de HCl

n= m : M

n= 54,75g : 36,5g/moli= 1,5 moli HCl

b.

ms= md.100 : c

ms= 54,75 .100 : 30=182,5 g sol. HCl

c.

y= 58,5 .60 : 40=87,75 g NaCl

n= 87,75 g : 58,5g/moli= 1,5 moli NaCl

M NaOH=23 + 16 +1=40-----> 40g/moli

MHCl= 1 + 35,5=36,5----> 36,5g/moli

MNaCl= 23 + 35.5= 58,5------> 58,5g/moli