I am doing an ice fishing lab for a project where you float an ice cube in water, put a cotton string on the ice cube, and sprinkle salt on the string so it sticks to the ice cube, making it able to be picked up.-- I am supposed to research all I can about every little aspect of the project, but there is some of it that I just do not seem to understand.

 

I know that NaCl is supposed to disrupt "the" equilibrium somehow, but I am not sure if it is just that the rate of state changes is disrupted or if there is something else I haven't found by research that could be "the" equilibrium. Could "the equilibrium" be referring to anything else?

 

Also, I tried the experiment with a couple other chemicals: MgSO4(big chunks of epsom salt) and NaCO3(baking soda). Magnesium sulfate didn't work, while sodium carbonate worked even better than sodium chloride. Is that supposed to happen? If it is, is it the sodium that made the NaCO3 work, or was it because the chunks of epsom salt were so big that the MgSO4 didn't work?

 

Maybe I'm just not so great at searching the web for research material, but I sure would be happy if someone could help me understand all of this!!

Did a quick search myself and found this:

 

"The salt separates the water molecules in the ice causing it to melt. After about a minute the salt is distributed and no longer disturbs the water molecules. The ice refreezes around the string."

 

I assume that the other salts you tried works in the same way, and that there were too much salt in the chunks to be distributed in that small area, causing it not to freeze.