Question

Which compartment has the higher osmotic pressure? Which compartment has the higher osmotic pressure? 1%% (m/vm/v) starch solution 10%% (m/vm/v) starch solution

Answer 1

Answer : The compartment that has the higher osmotic pressure is, 10 % (m/v) starch solution.

Explanation :

Formula used for osmotic pressure :

$\pi=\frac{nRT}{V}\\\\\pi=\frac{wRT}{MV}$

where,

= osmotic pressure

V = volume of solution

R = solution constant  = 0.0821 L.atm/mole.K

T= temperature of solution = $25^oC=273+25=298K$

M = molar mass of solute

w = mass of solute

Now we have to determine the osmotic pressure for the following solution.

For 1 % (m/v) starch solution :

1 % (m/v) starch solution means that 1 grams of starch present in 100 mL or 0.1 L of solution.

Molar mass of starch = 692.7 g/mol

$\pi=\frac{(1g)\times (0.0821Latm/moleK)\times (298K)}{(692.7g/mol)\times (0.1L)}$

$\pi=0.353atm$

For 10 % (m/v) starch solution :

10 % (m/v) starch solution means that 10 grams of starch present in 100 mL or 0.1 L of solution.

Molar mass of starch = 692.7 g/mol

$\pi=\frac{(10g)\times (0.0821Latm/moleK)\times (298K)}{(692.7g/mol)\times (0.1L)}$

$\pi=3.53atm$

From this we conclude that, 10 % (m/v) starch solution has the higher osmotic pressure as compared to 1 % (m/v) starch solution.

Hence, the compartment that has the higher osmotic pressure is, 10 % (m/v) starch solution.