Calculate, use hess’s law to determine /\H for the reaction NO(g) + O(g)—> NO2(g) /\H=? given the following reactions. show your work O2(g)—>2O(g)/\H= + 495 kJ
2O3(g)—>3O2(g)/\H = -427 kJ
NO(g) + O3(g)—> NO2(g) + O2(g) /\H= -199 kJ

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.

4d^55s^1 ( third choice)