Verified Solution • 2025–26 Session
moderate
QNEET-2024-Ch-29: NEET 2024 Chemistry - Class 12 NEET-2024-Ch-29 Solution: The plot of osmotic pressure (\( \)) vs concentration (mol…
The plot of osmotic pressure () vs concentration (mol ) for a solution gives a straight line with slope 25.73 L bar . The temperature at which the osmotic pressure measurement is done is (Use R = 0.083 L bar )
Multiple Choice Options
- A 3 7 _ C
- B 31 0 _ C
- C 25.7 3 _ C
- D 12.0 5 _ C
Step-by-Step Verified Solution
The relationship between the osmotic pressure ( _ ) of a solution and its concentration ( c ) can be derived from the van't Hoff equation for dilute solutions, which is given by:
_ = c R T
where:
_ is the osmotic pressure,
c is the concentration of the solution in moles per liter,
R is the ideal gas constant in appropriate units, and
T is the temperature in Kelvin.
According to the problem, the slope of the _ vs c plot is given as 25.73 L bar mol _ 1 which corresponds to the product R T from the van't Hoff equation. We are provided with the value of the gas constant R = 0.083 L bar mol _ 1 K _ 1 .
To find the temperature T , we use the following equation derived from the slope of the line:
R T = 25.73 L bar mol _ 1
To isolate T , we rearrange the equation:
T = 25.73 L bar mol _ 1 0.083 L bar mol _ 1 K _ 1 � 310 K
To convert this temperature from Kelvin to Celsius, we use the conversion formula:
T Celsius = T Kelvin _ 273.15
T Celsius = 310 K _ 273.15 � 36.85 _ C
This value is closest to 37 _ C , which corresponds to Option A. Therefore, the temperature at which the osmotic pressure measurement is done is approximately 37 _ C .