(a) Define the following terms:
(i) Mole fraction (ii) Van't Hoff factor
(b) `100mg` of a protein is dissolved in enough water to make `10.0 mL` of a solution. If this solution has an osmotic pressure of `13.3 mm Hg` at `25^(@)C`, what is the molar mass of protein?
`(R=0.821 L "atom mol"^(-1)K^(-1) "and" 760mm Hg=1` atm.)

Explanation

(a) (i) Mole fraction : Mole fraction (X) of a component in a mixture is the ratio between the number of moles of the componenet to the total number of moles of all the component of the mixture.
`:.X_(A)=("Mole fraction of componentA is given by moles of A")/("total moles of all the component of the mixutre")`
(ii) Van't Hoff factor : Van't Hoff factor is a correction factor defined as
`i =("Observed value of colligative property")/("Normal value of colligative property")`
(b) See Q. 20, Set -I , Delhi Boards , 2009.