What is the osmotic pressure formed by dissolving 50.8 mg of aspirin (C9H8O4) in 0.200 L of water at 18°C?
mols = grams/molar mass.Solve for mols.
M = mols/L. Solve for M.
pi = MRT. Solve for pi = osmotic pressure.
I did that. doesnt it have to be liters of the total solution? so how do we factor in the asprin into the liters?
I beg to differ but you did not do that. If you had you would have the answer now.
mols = 50.8E-3g/180.2 = about 0.0003 but you need to do it more accurately.
Then 0.0003 mols/0.200L = about 0.0014
Then pi = MRT
To calculate the osmotic pressure formed by dissolving a solute in a solvent, we can use the following formula:
π = (n/V)RT
Where:
π is the osmotic pressure in units of pressure (usually atmospheres, atm)
n is the number of moles of solute
V is the volume of the solvent in liters
R is the ideal gas constant (0.0821 L · atm / (mol · K))
T is the temperature in Kelvin (K)
Let's break it down step by step to calculate the osmotic pressure in this case.
1. Calculate the number of moles of aspirin (C9H8O4):
To find the number of moles, we can use the formula:
moles = mass / molar mass
The molar mass of aspirin (C9H8O4) is:
(12.01 g/mol * 9) + (1.01 g/mol * 8) + (16.00 g/mol * 4) = 180.16 g/mol
Converting the mass of aspirin to grams:
50.8 mg = 0.0508 g
Now, we can calculate the number of moles:
moles = 0.0508 g / 180.16 g/mol
2. Convert the temperature to Kelvin:
The given temperature is 18°C. To convert it to Kelvin, we need to add 273.15 (K = °C + 273.15).
T = 18°C + 273.15 = 291.15 K
3. Plug the values into the osmotic pressure formula:
π = (n/V)RT
n = 0.0508 g / 180.16 g/mol (calculated in step 1)
V = 0.200 L (given)
R = 0.0821 L · atm / (mol · K)
T = 291.15 K (calculated in step 2)
π = (0.0508 g / 180.16 g/mol) * (0.200 L) * (0.0821 L · atm / (mol · K)) * (291.15 K)
Calculating this expression will give you the osmotic pressure (π) formed by dissolving 50.8 mg of aspirin (C9H8O4) in 0.200 L of water at 18°C.