Science Buddies: "Ask an Expert"

Hello everbody,
On a previous post, i said i was doing the project Supercooling water and snap frezzing . They said to put salt but why? Can you help me to understand that? In my opion they do it to maintain the the tempature of the water and ice. Is that true?










Thanks
quangnguyen

Hi:

Your question:

put salt but why?

. I believe this is answered in the experiment:

The dissolved salt causes the bath to have a temperature below the normal freezing point of water. This pheonomenon is called freezing point depression.

I recommend using a search engine to investigate "freezing point depression". Good luck!

Keith

Hello Everyone,
Thanks Keith for answering.Now in eed to know this:How does adding salt to ice make it colder? This the project question . But is still don't get why the experiment prove this. Please answer me by tonight.










Thanks,
quangnguyen

Hello Everybody,
Sorry to be impaitent but please answer by tonight. PLEASE,PLEASE,PLEASE, answer by tonight









Sorry
quangnguyen

It doesn't make the ice colder. Salt lowers the freezing point of water. Normally water freezes at 32 degrees Farenheit/0 celsius. The addition of salt will lower the temperature at which water freezes so that the salt water solution is still a liquid below 32 degrees Farenheit/0 celsius. This effect will work for several degrees below the normal freezing point of water. So, this is why you put salt on your driveway in winter and the ice will melt, because the freezing point has been lowered.

╦µ╝£® Tyler

Hi
Please read my previous post - I answered that question. If you're asking a different question than I answered, could you try rephrasing it so I understand better? Thanks.

Keith