I am having trouble figuring out the calculations for osmotic pressure. This is what I need to do.
Indicate whether the osmotic pressure of a 0.1M NaNO3 solution will be less than , the same as , or greater than that each of the following solutions
a. 0.1M NaCl b. 0.1M KNO3 c. 0.1M Na2SO4 d. 0.1M Glucose
pi = i*M*R*T
R and T (and M) are constant; therefore, only i will affect pi.
i for NaNO3 = 2
i for KNO3 = 2
i for Na2SO4 = 3
i for glucose = 1
To determine which solution will have a greater osmotic pressure, we need to calculate the osmotic pressure of each solution. Osmotic pressure can be calculated using the formula:
π = nRT/V
Where:
- π is the osmotic pressure (in Pascal or atmospheres)
- n is the concentration of solute particles (in moles)
- R is the ideal gas constant (0.0821 L·atm/(mol·K) or 8.314 J/(mol·K))
- T is the temperature (in Kelvin)
- V is the molar volume of the solvent (in liters)
Let's calculate the osmotic pressure for each solution and compare them:
a. 0.1M NaCl:
Here, since NaCl dissociates into 2 ions (Na+ and Cl-), the concentration of solute particles (n) would be 0.1M x 2 = 0.2M. Now, substitute the values into the formula, ensuring that the temperature is in Kelvin.
b. 0.1M KNO3:
In this case, KNO3 dissociates into 2 ions (K+ and NO3-), so the concentration of solute particles (n) is 0.1M x 2 = 0.2M. Calculate using the formula.
c. 0.1M Na2SO4:
Na2SO4 dissociates into 3 ions (2Na+ and SO4 2-), so the concentration of solute particles (n) is 0.1M x 3 = 0.3M. Calculate using the formula.
d. 0.1M Glucose:
Glucose does not dissociate into ions, so the concentration of solute particles (n) is 0.1M. Calculate using the formula.
By comparing the osmotic pressures, you can determine which solution has a greater osmotic pressure. Remember, higher osmotic pressure means a higher concentration of solute particles.