Paul Sutton


Growing salt crystals – 2nd attempt

Following my previous attempt at this. I am now repeating the experiment with pure Sodium Chloride. I am also using a 250ml conical flask, which is much larger.

This time I used hot water from the kettle, taking a precaution of warming this up with warm tap water first, just in case the sudden temperature changed caused the flask to shatter. I then added Sodium Chloride powder.

Salt crystals 1

Salt crystals 2

I am now leaving this to hopefully grow some nice crystals which I would expect to be more of a cuboid shape. This prediction is based on:-

  • Pictures of similar results
  • The molecular shape of Sodium Chloride.

I am doing this for:

  • Support the STEM Group events
  • Hopefully can use this in a school to help children grow their own crystals.
  • Personal interest
  • Research purposes




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Growing Salt Crystals

Reposting this due to adding a link to a Science Forum post.

As Salt (Sodium Chloride) dissolves in water, you can grow salt crystals quite easily. There are lots of instructions on the internet, on how to do this with Salt, as well as other chemicals; such as, Alum (Aluminium Sulfate), Borax (Sodium Borate) for example.

For the purpose of my attempt, I used

*a conical flask from my old Chemistry set,
* a wooden lollipop stick, * string * paper clip (to hold the string in the solution)

This is illustrated in the first picture, while the 2nd is a photo of the resulting crystal formation.

Flask Crystals

Update 17/10/2021

I took more photos on the 4th October to illustrate further growth of the crystals

one two three

It is probably worth mentioning that table salt contains Sodium Chloride but also a Anti caking agent called Sodium Ferrycyanide which according to that wikipedia article is a yellow solid.

I am not sure if this somehow affects the growth or shape of the resultng crystals. At some point I should try the same experiment pure NaCl