Calculate osmotic pressure atm developed initially by each s

Calculate osmotic pressure (atm) developed initially by each solution. Show all work.

30% sucrose =

60% sucrose =

Solution

Osmotic pressure is expressed by the formula:

osmotic pressure ( in atm) = iMRT

Where i = van’t Hoff factor of the solute (sucrose)

M = molar concentration in mol/L

R = universal gas constant = 0.08206 L atm/mol K

T = absolute temperature in kelvin

Molar mass of sucrose = 342

N_sucrose = 30 g * 1 mol/342 g = 0.0877 mol

M_sucrose = N_sucrose / V_sucrose

             = 0.0877 mol / (100 ml * 1L/1000 ml)

             = 0.877 mol/L

Considering the temperature to be 25° C (25 + 273 = 298 K)

Since sucrose does not dissociate in water, thus van’t Hoff factor is 1.

Therefore osmotic pressure = 1 * 0.877 mol/L * 0.08206 L atm/ mol K * 298 K

= 21.45 atm

Similarly for 60%,

N_sucrose = 60 g * 1 mol/342 g = 0.175 mol

M_sucrose = N_sucrose / V_sucrose

             = 0.175 mol / (100 ml * 1L/1000 ml)

             = 1.75 mol/L

Considering the temperature to be 25° C (25 + 273 = 298 K)

Since sucrose does not dissociate in water, thus van’t Hoff factor is 1.

Therefore osmotic pressure = 1 * 1.75 mol/L * 0.08206 L atm/ mol K * 298 K

= 42.79 atm