Question

A solution of 62.4 g of a covalent compound in enough water to make 1.000 L of solution has an osmotic pressure of 0.305 atm at 25°C. Assume the covalent compound does not dissociate in the solution. Based on these data, what is the molar mass (in g/mol) of covalent? Round your answer to the nearest whole number and do not include units with your answer.

Answer 1

Answer:

4.99 × 10³ g/mol

Explanation:

Step 1: Given  and required data

• Mass of the covalent compound (m): 62.4 g

• Volume of the solution (V): 1.000 L

• Osmotic pressure (π): 0.305 atm

• Temperature (T): 25°C = 298 K

Step 2: Calculate the molarity (M) of the solution

The osmotic pressure is a colligative pressure. For a covalent compound, it can be calculated using the following expression.

π = M × R × T

M = π / R × T

M = 0.305 atm / (0.0821 atm.L/mol.K) × 298 K

M = 0.0125 M

Step 3: Calculate the moles of solute (n)

We will use the definition of molarity.

M = n / V

n = M × V

n = 0.0125 mol/L × 1.000 L = 0.0125 mol

Step 4: Calculate the molar mass of the compound

0.0125 moles of the compound weigh 62.4 g. The molar mass is:

62.4 g/0.0125 mol = 4.99 × 10³ g/mol