Question

va rog mult.... Am nevoie urgent

Answer 1

3. ro(densitatea)= m/v

m= 5,85g

v= v2-v1- =0,75ml

d= 5,85g/0.75ml= 7,8g/ml-------------------------> Fe

5b. c= mdx100/ms, unde ms= md+m,apa

md= 20gNaCl

ms= 20gNaCl +180gapa= 200g sol

c= 20x100/200= 10%

6b,c.

md= 30g

15= 30x100/ms---> ms= 200g

ms= md+m,apa---> m,apa= 200g-30g=170g