Osmotic Pressure & Mass Percent

Click For Summary
SUMMARY

The discussion focuses on calculating the mass percentages of KCl, KNO3, and Ba(NO3)2 in a solid mixture based on its osmotic pressure and chlorine content. The osmotic pressure of 744.7 mm Hg was converted to 0.9799 atm, leading to the calculation of ion concentration using the formula π = iCRT. The user determined that the mixture dissociates into 7 ions, resulting in a concentration of 0.0057 mol of ions per liter. The final solution involved setting up two equations with two variables to solve for the mass percentages of each component in the mixture.

PREREQUISITES
  • Understanding of osmotic pressure and its equation (π = iCRT)
  • Knowledge of molarity and molality concepts
  • Familiarity with dissociation of ionic compounds in solution
  • Basic algebra skills for solving simultaneous equations
NEXT STEPS
  • Study the Van 't Hoff factor (i) for different ionic compounds
  • Learn how to calculate molarity from osmotic pressure
  • Explore methods for solving systems of equations in chemistry
  • Investigate the properties and dissociation of KCl, KNO3, and Ba(NO3)2 in aqueous solutions
USEFUL FOR

Chemistry students, educators, and professionals involved in solution chemistry, particularly those focusing on osmotic pressure calculations and ionic dissociation in mixtures.

kuahji
Messages
390
Reaction score
2
[SOLVED] Osmotic Pressure & Mass Percent

A solid mixture of KCL, KNO3, and Ba(NO3)2 is 20.92 mass percent chlorine, and a 1.000g sample of the mixture in 500.0 mL of aqueous solution at 25 C has an osmotic pressure of 744.7 mm Hg. What are the mass percents of KCl, KNO3, and Ba(NO3)2 in the mixture?

First I started out using osmotic pressure equation after I converted 744.7 mm Hg to atm.

.9799atm=7x(.08206 L*atm*K^{-1}*mol^{-1})(298K)

x=.0057 mol of ions/liter (I chose 7x because it appears there would be 7 ions, assuming they'd all dissociate completely)

Here however is where I'm stuck already. Any advice on where to go from here?
 
Physics news on Phys.org
kuahji said:
A solid mixture of KCL, KNO3, and Ba(NO3)2 is 20.92 mass percent chlorine, and a 1.000g sample of the mixture in 500.0 mL of aqueous solution at 25 C has an osmotic pressure of 744.7 mm Hg. What are the mass percents of KCl, KNO3, and Ba(NO3)2 in the mixture?

First I started out using osmotic pressure equation after I converted 744.7 mm Hg to atm.

.9799atm=7x(.08206 L*atm*K^{-1}*mol^{-1})(298K)

x=.0057 mol of ions/liter (I chose 7x because it appears there would be 7 ions, assuming they'd all dissociate completely)

Here however is where I'm stuck already. Any advice on where to go from here?

From here determine how many moles of ions are in half a liter.
 
I was able to figure it out from here, though it wasn't pretty. I ended up having to make two equations with two different variables. Thanks.
 

Similar threads

Replies
3
Views
2K
Replies
1
Views
5K
  • · Replies 2 ·
Replies
2
Views
5K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
3
Views
4K
Replies
4
Views
6K
  • · Replies 7 ·
Replies
7
Views
25K
Replies
2
Views
2K