I know that in order to increase the rate of solvation, you need to increase how often solute and solvent particles come into contact.
You can do it by:
- agitating the mixture
- increasing the surface area of the solute
- heating up the solvent
But my question is: Does adding more solute (like adding more salt to water) increase the rate of solvation since the contact surface area is larger?
Edit: The original question in the book describes dissolving a certain amount of $\ce{NaCl}$ into water and asks, “What can be done to increase the rate of dissolution without affecting solubility?” I assume the rate is measured by how fast the mass of $\ce{NaCl}$ is consumed, which is $-\frac{dW}{dt}$.
Answer
If the answers are to be exclusive, then obvious choice is agitating the mixture.
If the answers are not to be exclusive, then agitating the mixture + increased surface by adding more solute increases $\frac{\mathrm{d}c}{\mathrm{d}t}$
Adding more solute does not increase rate of solvation, but as the absolute surface increases, it increases $\frac{\mathrm{d}c}{\mathrm{d}t}$.
Note also without affecting solubility from your comment, so increasing temperature is out.
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