6.00 g of hemoglobin was dissolved in 250.0 mL of solution. The resulting osmotic pressure was 6.80 mmHg at 23.0C. what is the molar mass of hemoglobin?
Convert 6.80 mm Hg to atmospheres. 6.80/760 = ? = pi (not 3.14 but pi in this case is osmotic pressure).
pi = MRT
pi from above.
You know R and T (remember T must be in kelvin).
Solve for M = molarity = mols/L
You know M and L, solve for mols.
Then mols = grams/molar mass. You know mols and grams, solve for molar mass.
Post your work if you get stuck.
got it! thanks so much
To find the molar mass of hemoglobin, we can use the formula:
Molar mass = (2 * R * T * Osmotic pressure) / (π * V)
Where:
- R is the ideal gas constant (0.0821 L*atm/(mol*K)),
- T is the temperature in Kelvin (23.0°C + 273.15 = 296.15 K),
- Osmotic pressure is the given value (6.80 mmHg),
- V is the volume of the solution in liters (250.0 mL = 0.250 L),
- π is the constant value for pi (approximately 3.14159).
Now let's substitute these values into the formula:
Molar mass = (2 * 0.0821 L*atm/(mol*K) * 296.15 K * 6.80 mmHg) / (3.14159 * 0.250 L)
First, let's simplify the units:
Molar mass = (2 * 0.0821 * 296.15 * 6.80) / (3.14159 * 0.250)
Molar mass = (2 * 0.0821 * 296.15 * 6.80) / 0.7853975
Now, let's calculate:
Molar mass ≈ 23910.86 g/mol
Therefore, the molar mass of hemoglobin is approximately 23910.86 g/mol.