Choose the correct statement(s) :
(Assume complete dissociation/association)
A
Van't Hoff factor for Ba(OH)2(aq.) is 2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
Van't Hoff factor for Ba(OH)2(aq.) is 3
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
Van't Hoff factor for CH3COOH in benzene is 2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
Van't Hoff factor for CH3COOH in benzene is 0.5
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution
The correct option is DVan't Hoff factor for CH3COOH in benzene is 0.5 van't Hoff factor(i)=Number of molecules (actual)Number of molecules (expected)
Ba(OH)2 is a strong electrolyte soits 100% dissociation occurs in an aqueous solution.
Ba(OH)2→Ba+2+2OH− i=3
Molecules of ethanoic acid dimerise in benzene due to hydrogen bonding. This normally happens in solvents of low dielectric constant. In this case number of particles are reduced due to dimerisation.
Association of molecules is depicted as follows:
Here i=0.5
Option (a) and (d) are correct
Theory :
Effect of Association
No of solute particles decrease
Colligative property (CP) decreases
Molar mass (MM) of solute increases
Observed MM > Expected MM