Question

Calculate the osmotic pressure of 20 m solution of LiCl at 25C

Answer 1

Answer:

979 atm

Explanation:

To calculate the osmotic pressure, you need to use the following equation:

π = i MRT

In this equation,

-----> π = osmotic pressure (atm)

-----> i = van't Hoff's factor (number of dissolved ions)

-----> M = Molarity (M)

-----> R = Ideal Gas constant (0.08206 L*atm/mol*K)

-----> T = temperature (K)

When LiCl dissolves, it dissociates into two ions (Li⁺ and Cl⁻). Therefore, van't Hoff's factor is 2. Before plugging the given values into the equation, you need to convert Celsius to Kelvin.

i = 2                             R = 0.08206 L*atm/mol*K

M = 20 M                    T = 25°C + 273.15 = 298.15 K

π = i MRT

π = (2)(20 M)(0.08206 L*atm/mol*K)(298.15 K)

π = 979 atm