At 300 K, the vapour pressure of an ideal solution containing 1 mole of A and 3 moles of B is 500 mm Hg. At the same temperature, 2 moles of B are added to this solution. The vapour pressure of solution increases by 10% of the original vapour pressure. Correct statements about the vapour pressure are

Explanation

It is due to adsorptions of `Fe^(3+)` ions on the surface of `Fe(OH)_(3)` which gives colloidal sol.
`Fe(OH)_(3) ("ppt.")+Fe^(3+)("ions adsorbed") rarr [Fe(OH)_(3)]Fe^(3+)` ("colloidal sol.)