Anish
Last Activity: 3 Years ago
Let M be the molecular weight of solute.
Number of moles of solute =
M
5.40
Number of moles of water =
18
90.0
=5
Mole fraction of solute =
M
5.40
+5
M
5.40
=
5.40+5M
5.40
Relative lowering in the vapour pressure =
P
0
P
0
−P
=
23.76
23.76−23.32
=0.01852
The relative lowering in the vapour pressure of the solution is equal to the mole fraction of solute.
0.01852=
5.40+5M
5.40
⟹5.40+5M=291.6
5M=286.2
⟹M=57.24 g/mol