A pair of  isotonic solutions, among the following, is (assuming temperature to be the same) :

1. 0.1 (M) urea and 0.1 (M) NaCl

2. 0.1 (M) urea and 0.2 (M) MgCl₂

3. 0.1 (M) NaCl and 0.1 (M) Na₂SO₄

4. 0.1 (M) Ca(NO₃)₂ and 0.1 (M) Na₂SO₄

The osmotic pressure of 5 % (mass-volume) solution of cane sugar at 150 °C (mol. mass of sugar = 342 g/mole) is:

The relationship between osmotic pressure at 273 K, when 10 gm glucose (P₁), 10 gm urea (P₂), and 10 gm sucrose (P₃) are dissolved in 250 ml of water, is-

1. P₁ > P₂ > P₃

2. P₃ > P₁ > P₂

3. P₂ > P₁ > P₃

4. P₂ > P₃ > P₁

An aqueous solution containing 1 g of urea boils at 100.25 °C. The aqueous solution containing 3 g of glucose in the same volume will boil at:
1. 100.75 °C
2. 100.5 °C
3. 100 °C
4. 100.25 °C

Preservation of fruits against bacterial action by adding sugar is an example of-

1. Exosmosis

2. Reverse-osmosis

3. Diffusion

4. Capillary action