The degree of dissociation ( α ) of a weak electrolyte, AxBy is related to van't Hoff factor (i) by the expression: 1. α=x+y+1i-1 2.α=x+y-1i-1 3. α=i-1x+y+1 4. α=i-1x+y-1

Van't Hoff factor (i) =  $\frac{Observed Colligative Property}{Normal Colligative Property}$

$AxBy1-\alpha \to xA+yx\alpha +yB-xy\alpha$  

Total Moles =  $1-\alpha +x\alpha +y\alpha$ =  $1-\alpha x+y-1$

$i=\frac{1+\alpha x+y-1}{1}$

$\Rightarrow \alpha =\frac{i-1}{x+y-1}$