You Have A Solution That Is Composed Of Either NaCl Or CaCl2. What Tests Would You Run To Identify The Compound?


3 Answers

Danielle Joynson Profile
"Oh the eternal question, is it Sodium Chloride or Calcium Chloride in this colourless solution? You may have been told the only sure way is utilising the classic taste test,if it tastes like the sea then it is Sodium Chloride (NaCl) solution. This is of course complete nonsense and you shouldn’t drink anything that you are not sure of, seriously do NOT drink the stuff!

The widely accepted and easiest test to perform is to try and make a kind of chalk out of it.

You need to source yourself some sodium carbonate (Na2CO3), make it into a solution and add it to the mystery mixture. If absolutely nothing happens, then you’ve got sodium chloride (NaCl), as you would still have sodium carbonate, more commonly known as washing soda or soda ash, swilling around your test tube and it would still be completely soluble, so you’d see nothing.

But if you see little bits of white powder appearing then you’ve got calcium chloride (CaCl3). These little bits of powder in the product would be CaCO3 or more commonly known as chalk and will precipitate out of solution as it’s very insoluble within water.

Another (and infinitely more fun way) is to boil the solution and ensure that you are left with the suspect item. Then burn the stuff. This is more widely known as a flame test. So crack out the Bunsen burner and stick it in a strong flame, making sure you use tongs, goggles, gloves and the usual safety paraphernalia. If the suspect item burns with an orangey yellow flame then you have got Sodium Chloride (NaCl). On the other hand it’s more orangey red than orangey yellow then you’ve got Calcium Chloride (CaCl2).
Dave Cowles Profile
Dave Cowles answered
Add a solution of Sodium carbonate, Na2CO2, to the mixture. If it is NaCl, nothing noticeable will happen since the least soluble product would be Na2CO2, which is still soluble, it is detergent. If it is CaCl2, the product would be CaCO2 or I believe Chalk, and the would precipitate out of solution, very insoluble in water. I am sure there are other ways but that is how I would do it quickly in a test tube.
Anonymous Profile
Anonymous answered
Add something that will form an insoluble compound with the calcium such as a sulfate compound.

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