Consider the following balanced final equation. no2 + co mc014-1.jpg no + co2 which is the correct step(s) for this reaction mechanism?

The overall reaction provided is as follows:

NO₂ + CO → NO + CO₂

The reaction proceeds under the following two step mechanism:

Step 1: NO₂ + NO₂ → NO + NO₃ (slow)

Two molecules of nitrogen dioxide react to form NO and NO₃ which is the slow step in the mechanism. The NO₃ that is formed goes on to react with the carbon monoxide that leads to the formation of NO₂ and CO₂ and this is the fast step in the mechanism.

Step 2: NO₃ + CO → NO₂ + CO₂ (fast)

Now we combine both reactions to get the overall reaction:

NO₂ + NO₂ → NO + NO₃
NO₃ + CO → NO₂ + CO₂
NO₂ + CO → NO + CO₂

The overall reaction agrees with the reaction provided in the question.

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.