Osmosis

Exercise 3

    

a) Which solution has the highest osmotic pressure, a $100\frac{g}{L}$ glucose $C_6H_{12}O_6$ solution or a $100\frac{g}{L}$ sucrose $C_{12}H_{22}O_{11}$ solution at $ 27^oC $? b) What should be the temperature difference for the osmotic pressures to be equal? Comment!

a) $[sucrose]=\frac{100}{342}\lt \frac{100}{180}=[glucose]$ so: $\pi_{sucrose}=[sucrose]RT\lt [glucose]RT = \pi_{glucose}$ b) $\frac{100}{342}RT_1= \frac{100}{180}R\cdot 300$ $T_1=570\;K$ $\Delta\;T=270K$ Impossible (boiling!)