Question

I am planning an experiment for a school project. I have roughly 50 minutes (not including equipment preparations) to perform my experiment, which aims to experimentally verify how Ksp changes with temperature. Traditional methods such as oven drying would not work because it would take way too long for the sample to be dried. I don't have a specific compound in mind that I want use, but my thought process is as follows:

Add a poorly soluble (Ksp on the order of 10^-2) compound to distilled water
Stir either with flask or magnetic stir bar
Vacuum filter the remaining solid
Dry the sample within roughly half an hour, if possible
Record the mass that was not dissolved, to get the mass that was dissolved and calculate Ksp from there
I don't have much experience in the lab, so I am looking suggestions of methods for quickly drying a sample. Would it be more effective to get the Ksp using another method, such as measuring the electrical conductivity of the solution, instead of getting the mass?

Answer 1

To quickly dry a sample for your experiment on how Ksp changes with temperature, consider using a vacuum oven. Instead of measuring the mass of the dissolved compound, it may be more effective to measure the electrical conductivity of the solution to determine the solubility.

Step-by-step explanation:

When conducting your experiment to verify how Ksp changes with temperature, it may be more effective to measure the electrical conductivity of the solution instead of getting the mass. This is because the solubility product constant (Ksp) is a measure of the equilibrium concentration of ions in a saturated solution and can be related to electrical conductivity.

To quickly dry a sample, you could consider using a method such as heating the sample under reduced pressure in a vacuum oven. This would help remove the moisture from the sample faster than traditional methods like oven drying.

Here is a possible step-by-step procedure for your experiment:

1. 
   
3. Add a poorly soluble compound to distilled water.
4. 
   
6. Stir the mixture either with a flask or magnetic stir bar to ensure thorough mixing.
7. 
   
9. Vacuum filter the remaining solid to separate it from the solution.
10. 
    
12. Dry the sample using a vacuum oven or other suitable method that can achieve the desired drying time.
13. 
    
15. Measure the electrical conductivity of the solution to determine the solubility and calculate Ksp.