Sciencemadness Discussion Board

chlorate/nitrate test

condennnsa - 4-5-2017 at 00:35

I have 1kg of an unlabeled salt that I know is either NaNO3 or NaClO3.
What are the ways i could test this? thanks

nezza - 4-5-2017 at 01:21

Dissolve some of the unknown in water and add potassium chloride solution. (May need to be moderately concentrated). A crystalline precipitate should form if the material is potassium chlorate as potassium chlorate is only sparingly soluble in water. Potassium nitrate will not precipitate out. Alternatively if you have concentrated sulphuric acid add 1 or 2 DROPS only to a small (20mg or so) sample of the solid and warm. A series of sharp cracking sounds indicates the presence of chlorate as chlorine dioxide will be produced which explodes immediately. With nitrate brown NO2 fumes will be evolved.

Dmishin - 4-5-2017 at 07:51

For example, make NaOH solution, add some salt then drop some aluminium. Nitrate would be reduced to NH3, that can be detected by smell or with indicator.

Or just crystallize a small portion of the salt solution and look at it with good magnification. Chlorate gives cubic crystals, while nitrate crystals are rhombic.

Bert - 4-5-2017 at 10:25

Mix a SMALL pinch with Sulfur. Put on steel surface. Tap with hammer... ignition or explosion = chlorate.

Mix a little bit with powdered sugar. Put a small drop of concentrated H2SO4 on the pile, without any body parts too close to the chemicals, in a location where a fire would be safe... ignition = chlorate.