Question

For `[CrCl_(3).xNH_(3)]`, elevation in `b.pt` of one molal solution is triple of one molal aqueous solution of urea. Assuming `100%` ionisation of complex molecule, calculated the value of `x`.

Answer 1

`[CrCl_(3). xNH_(3)]` is complex which on `100%` ionisation gives a complex ion and ionised `Cl^(-)` ions.
Since `DeltaT_(b)` complex `=3xxDeltaT_(b)` urea
Thus complex molecule should furnish three ions. Therefore complex is
`[CrCl.xNH_(3)]Cl_(2) rarr [CrCl.xNH_(3)]+2Cl^(-)`
Also co-ordination number of `Cr` is six. thus `x=5`