Question

The osmotic pressure of a solution containing 7.0 g of insulin per liter is 23 torr at 25 °C. Assuming ideal solution behavior, what is the molar mass of insulin?

a) 552 g/mol
b) 110 g/mol
c) 220 g/mol
d) 440 g/mol

Answer 1

To calculate the molar mass of insulin, we can use the formula: Osmotic Pressure = (molarity * R * temperature) / molar mass. By rearranging the formula and plugging in the given values, we can solve for the molar mass of insulin, which is 220 g/mol (c).

Step-by-step explanation:

To calculate the molar mass of insulin, we can use the formula:

Osmotic Pressure = (molarity * R * temperature) / molar mass

We are given:

• Osmotic Pressure = 23 torr
• Insulin concentration = 7.0 g/L
• Temperature = 25 °C

By rearranging the formula and plugging in the values, we can solve for the molar mass of insulin:

Molar mass = (molarity * R * temperature) / osmotic pressure

Molar mass = (7.0 g/L * 0.0821 atm·L/(mol·K) * 298 K) / 23 torr

Molar mass = 220 g/mol

Therefore, the molar mass of insulin is 220 g/mol, option c).