Effect of particle size on boiling point in solution

In summary, when dissolved in water, the size of the particles increases and this causes the boiling point to increase. This is specific to G1 chlorides, and does not depend on the salt or the group.
  • #1
albertrichardf
165
11
Hello.
Suppose you dissolve something in water. I know that the boiling point should increase because as the water boils the solute's entropy decreases, and the net entropy should increase.
Now suppose, that I dissolve GI chlorides in the water. Each solution of the salt has the concentration, and because they are all from the same group they should react similarly. As I go down the group, the size of the particles increases. My question is as this particle size increases, how does the increase in boiling point change?

My guess is that as solute size increases, the solution's particles have less possible arrangements, so its entropy will decrease. Thus the boiling point will increase with size. Is that correct? And are there any other factors? Also, if I was to conduct a fair test of this, is it more important to keep the number of moles constant or the mass of the solute constant. Finally, is this a trend specific to G1 chlorides, or does it depend on the salt, and on the group?
Thank you for answering my questions. Also, if you know of sources for such data, I would appreciate if you could post them as well.
 
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  • #3
Thanks for the link. I would not expect the ebullioscopic constant to change, since that would depend entirely on the water, nor would I expect the Van't Hoff factor to change, since according to wikipedia, it is around 2 for GI chlorides. However, I am a bit confused about the given equation for the molality of the solution.

The molality is defined as the number of moles per unit mass in a solution, but according to the given equation there is the molality of the solution and the molality of the solute. The molality of the solution is equal to the molality of the solute times the Van't Hoff number. But I don't understand what would be the molality of the solute, because there is no mass of solution involved. Unless the molality of the solute is the number of moles per unit mass of solution, and the molality of the solution is the number of moles per unit mass of solution multiplied by the Van't Hoff number. Is that right?
 
  • #4
The molality of the solute is the number of moles of solute per unit mass of solvent. The molality of the solution is the number of moles of dissolved species per unit mass of solvent. This is equal to the molality of solute multiplied by the van't Hoff number. For example, if NaCl is completely dissociated into ions, a 1 molal solution of NaCl (solute molality) contains 2 moles of ions per kg water, so the solution molality is 2. (Actually from the article vH no = 1.9, but just for simplicity of illustration.)
 
  • #5
I see, thank you for the explanation. Thus according to the equation, if the number of moles remains constant, the boiling point increase should not change, but if the mass of solute remains a constant, the boiling point increase should decrease.
 
  • #6
Yes, if you're assuming the molar mass increases (and vH no. remains the same).
 
  • #7
mjc123 said:
Yes, if you're assuming the molar mass increases (and vH no. remains the same).
The vH should remain close to two for GI Cl salts if I understood the wikipedia article. Thank you for answering
 

Related to Effect of particle size on boiling point in solution

What is the purpose of studying the effect of particle size on boiling point in solution?

The purpose of this study is to understand the relationship between particle size and boiling point in solutions. This information can be useful in various industries such as pharmaceuticals, food and beverage, and environmental science.

How does particle size affect the boiling point of a solution?

Smaller particles have a larger surface area compared to larger particles, which results in stronger intermolecular forces and a higher boiling point. This is because more energy is needed to break the bonds between smaller particles.

What factors can influence the effect of particle size on boiling point in solution?

The type of solvent, concentration of solute, and temperature can all influence the effect of particle size on boiling point in solution. Other factors such as pressure and presence of impurities can also play a role.

How is the boiling point of a solution with smaller particles different from that of a solution with larger particles?

A solution with smaller particles will have a higher boiling point compared to a solution with larger particles. This is because smaller particles have stronger intermolecular forces, which require more energy to overcome and reach the boiling point.

What are some real-world applications of the effect of particle size on boiling point in solution?

Understanding the effect of particle size on boiling point in solution is important in various industries. For example, in the pharmaceutical industry, it can help determine the most effective way to administer medication. In the food and beverage industry, it can impact the taste and texture of products. In environmental science, it can be used to study the behavior of pollutants in solutions.

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