Ammonia and oxygen react to form nitrogen monoxide and water, like this:
4nh3
(g)
+
5o2
(g)
→
4no
(g)
+
6h2o
(g)
write the pressure equilibrium constant expression for this reaction.

4NH3+5O2 <=>4NO + 6H2O

Using the definition of Kp, we have
Kp=(Pno^4*Ph2o^6)/(Pnh3^4*Po2^5)
where Pno=partial pressure of NO, etc.

The numerical value for a given temperature can be evaluated when the actual partial pressures are known.

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.