The osmotic pressure of `0.010 M` potassium iodide solution `(KI)` at `25^(@)C` is `0.465 atm`. Calculate the van't hoff factor for `KI` at this concentration.
Strategy: Use the modified equation `(2.78)` to account for the effect of dissociation of KI in water.

Explanation

From equation `(2.78)`, we can write
`i=pi/(CRT)=((0.465 atm))/((0.010 mol L^(-1))(0.0821 (L atm)/(K mol))(298 K))`
`=1.90`