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--- chemical:hno3:distillation [2012/10/07 05:03] – mcmaster
+++ chemical:hno3:distillation [2018/09/05 17:00] (current) – [References] mcmaster
@@ Line 62: / Line 62: @@
 {{:chemical:hno3:distillation:healthy_bubbles.jpg?300|}}
-Once it gets hot enough the KNO3 will completely dissolve in the H2SO4.  It should give a healthy bubble like above.  Try not to let the level exceed halfway.
+Once it gets hot enough the KNO3 will completely dissolve in the H2SO4.  It should give a healthy bubble like above.  Try not to let the level exceed halfway.  Its fine if the mixture is only bubbling at top and is liquid at bottom (ie just at the boiling point).
 This works okay but takes a while to heat up (30-45 minutes typical IIRC).  Helped a little to put aluminum foil over the still.  Overall, the probably was that the Vireux condenser was overkill for the level of purity I require.
@@ Line 222: / Line 222: @@
 Don't try to pour old the hot H2SO4 / KNO3 biproduct (KHSO4).  It will likely solidify on the cooler upper half of the flask and close it off.  This can cause pressure to build from the still hot bottom cooking off.  Instead, wait until its cool and then add water.  It will likely take a number of washings to get it all out.  Warm water and sloshing it around so that it breaks up and not just dissolves helps.  I blow the flask with a fan to help it cool down faster.  The more acid you use the more acid that will be leftover and keeping the mixture liquid.  Above: KHSO4 waste product.
+====== References ======
+http://www.sciencemadness.org/talk/viewthread.php?tid=13090&page=2
+  * Persulfate to reduce NO2