A) Raoult?s law states that the vapor pressure of a component over a solution is proportional to its mole fraction
B) The osmotic pressure\[(\pi )\]of a solution is given by the equation\[\pi =~MRT,\]where M is the molarity of the solution
C) The correct order of osmotic pressure for M aqueous solution of each compound is \[BaC{{l}_{2}}>KCl>C{{H}_{3}}COOH>\]sucrose
D) Two sucrose solutions -of same molality prepared in different solvents will have the same freezing point depression
Correct Answer: D
Solution :
\[{{P}_{A}}={{X}_{A}}{{p}^{o}}A;\]true \[\pi =iMRT=MRT;\]true (if van't Hoff factor \[i=1\]) \[i=[1+(y-1)x]\] \[y=\]number of ions \[x=\]degree of ionisation \[i=3\]for\[BaC{{l}_{2}}x=1\] (strong electrolyte) \[i=2\]for\[KCl\text{ }x=1\] (strong electrolyte) \[i=(1+x)\]for \[C{{H}_{3}}COOH\text{ }x<<1\] (weak) \[i=1\]for sucrose (non-electrolyte) \[i\] (for\[BaC{{l}_{2}}\])\[>KCl>C{{H}_{3}}COOH>\]sucrose Thus, (c) is also true. (d)\[\Delta {{T}_{f}}={{k}_{f}}m.\] \[{{K}_{f}}\]is dependent on solvent. Thus freezing points [\[=T\](solvent)\[-\Delta {{T}_{f}}\]) are different. Thus, (d) is false.
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