Question

Which solution will have the lowest vapor pressure?

a.) 0.10M HCLO₂

b.) 0.15M Glucose

c.) 0.050M NaCl

d.) 0.080M Mg(NO₃)₂

Answer 1

more solute particles lowest the vapour pressure

collegative property = i x M

where i = vant half facter

M = concentration Molarity

HClO2 can dissociate as a H+ + ClO2^- so i= 2

concentration of ions = 2 x 0.1 = 0.2M

0.15M Glucose  

glucose cannot dissociate so

so i= 1

= 1 x 0.15 = 0.15M

0.050M NaCl

NaCl ---> Na+ + Cl-

i = 2

=1xM = 2 x 0.05 M = 0.1

0.080M Mg(NO₃)₂

Mg(NO₃)₂   ---> Mg2+ + 2NO3^-

i = 3

= 3 x 0.08 = 0.24

so correct naswer is option D