In the reaction 2NO (g) + O2 (g) --> 2NO2 (g) . Which species has the highest rate of consumption (decrease)?
O2
NO2
NO
All species have the same rate

NO

Explanation:

Because as the reaction proceeds,it is consumed by a factor of 2moles.

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.