Osmotic Pressure

The plot of osmotic pressure (Π) vs concentration (mol L^-1) for a solution gives a straight line with slope 25.73 L bar mol^-1. The temperature at which the osmotic pressure measurement is done is:

(Use R = 0.083 L bar mol^-1 K^-1)

Solution:

The osmotic pressure (Π) is given by the equation:

Π = CRT

where:

• Π is the osmotic pressure
• C is the concentration (mol L^-1)
• R is the ideal gas constant (0.083 L bar mol^-1 K^-1)
• T is the temperature in Kelvin

Rearranging the equation, we get:

Π = (RT)C

This equation is in the form of a straight line, y = mx, where:

• y = Π
• x = C
• m = RT (slope)

Given the slope (RT) = 25.73 L bar mol^-1 and R = 0.083 L bar mol^-1 K^-1, we can find the temperature (T):

T = slope / R

T = 25.73 / 0.083

T ≈ 310 K

To convert Kelvin to Celsius, we subtract 273.15:

T (°C) = T (K) - 273.15

T (°C) = 310 - 273.15

T (°C) ≈ 36.85°C

This is approximately 37°C

Option 1: 37°C