Calculate the osmotic pressure of a solution prepared by dissolving 65.0 g of Na2SO4 in enough water to make 500 mL of solution at 20°C. (Assume no ion pairing – in other words, assume that the electrolyte completely dissociates into its constituent ions.)

66.0 atm

Explanation:

We can calculate the osmotic pressure (π) using the following expression.

where,

Step 1: Calculate i

Sodium sulfate completely dissociates according to the following equation.

Na₂SO₄ ⇒ 2 Na⁺ + SO₄²⁻

Since it produces 3 ions, i = 3.

Step 2: Calculate M

We can calculate the molarity of Na₂SO₄ using the following expression.

Step 3: Calculate T

We will use the following expression.

K = °C + 273.15

K = 20°C + 273.15 = 293 K

Step 4: Calculate π