Science Buddies: "Ask an Expert"

Does my daughter need calcium chloride monohydrate or dihydrate for this experiment?

Hello,
Thanks for posting your question on this forum.
I assume you are referring to the following experiment:
https://www.sciencebuddies.org/science- ... background

Based on the chemical equation provided , the experiment calls for calcium chloride anhydrous ( that means no water). However,I don't see there is any points that you need to use water-free CaCl2 since you are going to disslove it in the water anyway. The only difference between anhydrous,monohydrate and dihydrate is the number of water molecules attached to a single CaCl2 molecues ; hence the molecular mass of each chemicals are different in which you don't need to worry about in this experiment.

I haven't do this experiment myself, so I don't know if there is any practical reasons that requires calcium chloride anhydrous, but both monohydrate and dihydrate should work.
Hope it helps !
Pak

Hello!
If you are interested in coagulation a great topic to look into is the effect of snake venom on coagulation. I have come across a few videos online that clearly demonstrate what poison does to blood. A great way to see how your experiment pertains to the real world! (If you are very afraid of snakes this may not be a video for you!)
https://www.youtube.com/watch?v=4WvnjCkLbvY

Lily