Question

Pepsin is an enzyme involved in the process of digestion. Its molar mass is about 3.50 × 104 g/mol. What is the osmotic pressure in mm Hg at 30°C of a 0.500-g sample of pepsin in 60.0 mL of an aqueous solution?

Answer 1

Answer:

4.49 mmHg

Explanation:

Formula for osmotic pressure → π = M . R . T

M → molarity

Let's determine the moles of pepsin (mass / molar mass)

0.5 g / 35000 g/mol = 1.43 mol ×10⁻⁵ moles

These moles are in 60 mL of an aqueous solution. Let's determine M (mo/L)

1.43 mol ×10⁻⁵ mol / 0.060 L = 2.38×10⁻⁴ M

Noticed we changed the volume from mL to L → 60 mL . 1L/1000mL

T → T°K = T°C + 273 → 30°C +273 = 303K

Now we can put data on the formula:

π = 2.38×10⁻⁴ mol/L . 0.082 L.atm/mol.K . 303K

π = 5.91×10⁻³ atm

Let's convert the atm to mmHg

5.91×10⁻³ atm . 760mmHg / 1atm = 4.49 mmHg