Question

Which one has more Osmotic Pressure (O.P.) and why?

a) 1 M Glucose
b) 1 M NaCl

Show the calculative method.

Answer 1

1 M NaCI
hope it helps....

Answer 2

the osmotic pressure for NaCL and glucose.

Osmotic pressure = icRT

where i = van't Hoff factor

c = concentration in molarity

R= gas constant; 0.08206atm-l/mole-K

T= temperature in kelvin

Since there is no temperature indicated, we will try to use 298K (or room temperature) for the both solutions.

for 1M glucose

Osmotic P = (1)(1mole/L) (0.08206atm-l/mole-K) (298K)

= 24.45atm

**van't Hoff factor (i)=1 because glucose do not dissociate into ions when it is in the solution.

for 1M NaCl

Osmotic P = (2)(1mole/L) (0.08206atm-l/mole-K) (298K)
= 24.45
= 48.91 atm


**van't Hoff factor (i)=2 because NaCl dissociates into ions when it is in the solution. NaCl ---> Na+ + Cl-

We can simply picture it out as: there are more particles in 1M NaCl than in 1M glucose because of dissociation.

so we can say that 1m NaCl is more hypertonic.