Chemistry of Fireworks....?

Question

what is the decomposition reacitn of KNO3?....
KNO3-->K + NO3?

it says nitrate ions give up 1/3 of their oxygen...doesn't look like it in the equation...help!?

Answer 1

well. if you want the complete equation it would be like this:

KNO3 decomposes with the application of intense heat as in a fireworks display.

heat
KNO3 -----------> K + NO3

this is a correct equation. but if you want to display how oxygen is lost by the nitrate you have to include this equation:

NO3 -------------> NO2 + O2

you get 1/3 of NO3's oxygen so you deduct one oxygen ending up with NO2. But why O2. because remember that Oxygen exists as a diatomic gas(it is always in form as a gas with 2 molecules os O combined.)

so combining the two equations you have:

heat
KNO3------------> K + NO2 + O2

but wait. this is not the balanced equation yet. you have to balance it so that it agrees with the law of conservation of mass. here is the final balanced equation:

heat
2KNO3 ------------> 2K + 2NO2 + O2

Hope I answered your question.

Answer 2

KNO3 --> 1/2K2O + 5/4O2

O2 released is 39.6% which is like a little higher than 1/3

Answer 3

nitrates further decompose to nitrites giving off some oxygen and NO2

Answer 4

NO2 is probably one of the products.