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I thought it'd dissolve... but am i wrong? I added calcium chloride to water, and it was smoking, i was so confused. Can someone explain happened? I am doing an experiment where i dissolve salts in water, but im very confused now.

PS - my other salts are barium chloride, strontium chloride and magnesium chloride. Are these safe to use?

Raze XIX
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  • Have you used anhydrous CaCl2,, dihydrate or hexahydrate ? – Poutnik Sep 28 '20 at 12:07
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    You should not experiment with substances if you have lack of knowledge of their chemical properties and behaviour. It may forgive you few times, but it may cause severe injuries if not so lucky. Note that soluble baryum salts are poisonous. – Poutnik Sep 28 '20 at 12:12
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    Say the experiments should be done having some experience and proper safety precautions. For basic chemistry better reading first – Alchimista Sep 28 '20 at 12:16
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    I must emphasize once again, do not perform experiments if you don't know what you are doing. Prior knowledge is very important. Chemicals are not candies. It can cause serious injuries if you are not careful. – Nilay Ghosh Sep 28 '20 at 12:25
  • anhydrous calcium chloride. pretty sure strontium chloride and barium chloride are dihydrate or hexahydrate? – Raze XIX Sep 28 '20 at 15:39

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Have you used anhydrous $\ce{CaCl2}$, dihydrate $\ce{CaCl2 . 2 H2O}$ or hexahydrate $\ce{CaCl2 . 6 H2O}$ ( 3 most common forms) ? It is a big difference in the resulting thermal effect.

Hexahydrate causes cooling down of the solution while being dissolved. If ice is used instead of water, as the mixture hexahydrate : ice 2 : 1, it forms the famous freezing mixture, cooling itself down to $\pu{ -50 ^{\circ}C}$.

Anhydrous calcium chloride causes heating up while being dissolved. It is because of releasing energy of ion hydration. Rather then smoking, it was condensed water vapor.

Dihydrate is somewhere between, with roughly neutral thermal effect.

Interaction of the group 2 element chlorides with water is generally safe. There is very slight hydrolysis, growing progressively upwards along the group. The beryllium chloride hydrolysis is significant, releasing hydrogen chloride. Note that barium and especially beryllium are poisonous.

Poutnik
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  • "Aside of dissolution enthalpy, group II chlorides do not react with water, so they are safe.". Beryllium chloride would react significantly, producing hydrochloric acid/HCl gas. But then again, our aspiring chemist is not at a good stage to work with beryllium compounds anyway. Clarified this paragraph. – Oscar Lanzi Sep 28 '20 at 13:27
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    Well, I included just elements OP considered, but you are obviously right. But beryllium is rather a honourable member of the group 13. – Poutnik Sep 28 '20 at 13:47
  • So, to clarify, barium chloride dihydrate/hexahydrate are not safe? – Raze XIX Sep 28 '20 at 15:40
  • I have provided no information about existence of particular BaCl2 hydrates. Saying A is OK/exists says nothing about if B is OK/exists. Soluble barium salts are poisonous and therefore not safe. The best way for you is to buy/borrow of a textbook of anorganic chemistry. A good one is 2 volume "Chemistry of elements" by Greenwood/Earnshaw ( I hope I remember the title/authors well). Search also for book references withing CH SE. The second-best is reading the element articles on Wikipedia and following mentioned references. – Poutnik Sep 28 '20 at 16:03
  • @Raze XIX : P.S.: See resources-for-learning-chemistry – Poutnik Sep 29 '20 at 11:41