Monday, January 23, 2017

ice, salt, and food coloring

In January our land is usually covered in a foot of snow, but this year we have seen a lot of rain and temperatures hovering right around the freezing point. This is the year that I learned how to put snow chains on my tires in order to navigate the iced-over hilly roads near us. We stay home as much as possible when conditions become severe, but when our country driveway looks like an ice-skating rink for a week it's nice to have the option to throw some chains on the tires, kick in the 4-wheel drive, and venture out. Also, I have a job now, so it's helpful if I show up when I'm supposed to. :) 

I recently started as the new part-time library assistant in a beautiful, little 100+ year old library. I work a few afternoons a week and, so far, it is fitting in well with our homeschooling. I'm feeling so grateful that my husband mostly works from home and that his job (as a software developer) allows him to be flexible.

In order to make the roads passable, the local road crews sprinkle a mixture of salt and sand on the hills and curves. The girls and I were discussing how the sand provides some traction and the salt functions to lower the freezing temperature of the ice when I remembered a simple looking ice experiment that I had bookmarked ages ago. That evening I stuck some bowls full of water outside to freeze overnight. I was glad that I din't have to mess around with bowls of water in the freezer. Knowing my luck, they would have found a way to get tipped over before they froze. 

The next day we set the ice on some baking sheets, filled a dish with salt, mixed some cups of water and food coloring , and set out some droppers. When the girls initially sprinkled salt on the ice they noticed how quickly it began to melt little divots into the smooth surface of the ice.

 The coloring served to illustrate what was happening where the salt was taking action.



We alternated between salt and food coloring and began to see the salt melting deeper into the ice and beginning to form little cracks and fissures.

 This held their attention for much longer than I had originally supposed it would.



 At one point we flipped the ice over to be able to start on a fresh, smooth surface again.




 Eventually, there were melted pathways all the way through the ice.

This was a fun way to learn a little more about why they spread salt on icy roads. And it was pretty. I love it when things work out like that.

mini icicles everywhere

 For contrast, here is a more typical Wisconsin winter view from earlier in January of Sylvia, Ayla, and two of their friends on the morning after a sleepover.
I rather prefer snow to freezing rain.

"When snow falls, nature listens." ~ Antoinette van Kleeff