An auueous solution sontaining 4.9 g of solute dessolved in 500 mL of solution shows an osmoticpressure of 2.1 atmosphere at k 27^(@)C. What is the nature of the solute (assciated of dissoviated) if the molar mass of the solute is 57.4 amu ?

An auueous solution sontaining 4.9 g of solute dessolved in 500 mL of

1.	An auueous solution sontaining 4.9 g of solute dessolved in 500 mL of solution shows an osmoticpressure of 2.1 atmosphere at k 27^(@)C. What is the nature of the solute (assciated of dissoviated) if the molar mass of the solute is 57.4 amu ?
Answer» Solution :Step I. Calculation of observed molar mass of the solute `pi=CRT=(W_(B)xxRxxT)/(M_(B)xxV)or M_(B)=(W_(B)xxRxxT)/(pixxV)` `W_(B)=4.9, R=0.0821"L atm K"^(-1)mol^(-1), T=27+273=300 K` `V=500 mL=0.5 L, pi=2.1 atm.` `M_(B)=((4.9g)XX(0.0821" L atm K"^(-1)mol^(-1))xx(300K))/((2.1"atm")xx(0.5 L))=114.9" g mol"^(-1)`. Step II. Predicting the nature of the solute `"Normal molar mass of the solute "=57.4" g mol"^(-1)` Since the observed molar mass of the solute is more than its normal molar mass, this means that the solute has undergone association in solution.