Sciencemadness Discussion Board

Preparation of ionic nitrites

Irene - 20-5-2006 at 08:20

I've done the reduction of molten KNO3 with Pb in order to make KNO2.I extracted KNO2 from PbO after putting the crucible in hot water.Then I concentrated the solution and put HNO3 to neutralize it.At last I concentrated it to dryness and took yellow granules of KNO2.Why is neutralization necessary in this experiment?

12AX7 - 20-5-2006 at 08:26

Nitrate breaks down, releasing N2 gas. Also, nitrite is probably reduced to elemental nitrogen, similar to the less common but still smelly sulfate reduction when reacting the acid with iron or zinc (giving off some H2S).

Tim

Magpie - 20-5-2006 at 18:20

I have made NaNO2 using Pb. My procedure did not call for neutralization with HNO3.

See this thread: http://www.sciencemadness.org/talk/viewthread.php?tid=52#pid...

Coincidentally, it has the same title.