# Rate of reactions vs. HEat energy evolves per second inititally

1. Oct 22, 2012

### yannguyen

Nitrogen dioxide reacts with carbon monoxide by the overall equation:

NO2(g) + CO(g) ----> NO(g)+ CO2(g)

At a particular temperature, the reaction is second order In NO2 and zero order in CO. The rate constant is 0.515 L/(mol*s). How much heat energy evolves per second initially from 3.50 L of reaction mixture containing .0250 M NO2?

Assume the enthalpy change is constant with temperature.How much heat energy evolves per second initially from 3.50 L of reaction mixture containing .0250 M NO2?

I figured out the rate law for this = k[NO2]^2
The enthalpy change for NO2 is 33.1 kJ/mol
However I don't really understand how the concentration, the volume, and the rate constant would relate to find out the heat energy?

Should i find the number of moles of NO2 or what should I do? I totally have no idea about this!

Any help would be highly appreciate

2. Oct 23, 2012

### Staff: Mentor

How much energy would evolve during a second if there were 1 mole of NO2 produced per second? And if there were 0.5 mole produced? And if there were n moles produced?