1. The reaction between \( \mathrm{NO}(g) \) and \( \mathrm{NO}_{3}(g) \) is represented by the equation below. \( \mathrm{NO}(g)+\mathrm{NO}_{3}(g) \rightarrow 2 \mathrm{NO}_{2}(g) \) a. Most collisions between a molecule of NO and a molecule of \( \mathrm{NO}_{3} \) do not produce a reaction. Explain.

According to **collision theory**, for a chemical reaction to occur when two molecules collide, two main criteria must be met: 1. **Sufficient Energy (Activation Energy):** The colliding molecules must possess enough kinetic energy to overcome the activation energy barrier of the reaction. This energy is required to break existing bonds and form new ones during the transformation from reactants to products. 2. **Proper Orientation:** The molecules must collide in a specific orientation that allows the appropriate bonds to break and new bonds to form efficiently. Applying this to the reaction between \( \mathrm{NO}(g) \) and \( \mathrm{NO}_{3}(g) \): \[ \mathrm{NO}(g) + \mathrm{NO}_{3}(g) \rightarrow 2\,\mathrm{NO}_{2}(g) \] - **Energy Requirement:** Not every collision between \( \mathrm{NO} \) and \( \mathrm{NO}_{3} \) molecules will have enough kinetic energy to surpass the activation energy needed for the reaction to proceed. Many collisions may result in the molecules simply bouncing off each other without any chemical change. - **Orientation Necessity:** Even if sufficient energy is present, the molecules must align correctly during the collision to allow the formation of the new \( \mathrm{NO}_{2} \) bonds. Misaligned collisions won't facilitate the transformation into products. As a result, **only a small fraction of the total collisions** between \( \mathrm{NO} \) and \( \mathrm{NO}_{3} \) molecules will meet both the energy and orientation requirements necessary for the reaction to occur. The majority of collisions lack either the necessary energy, the proper alignment, or both, and thus do not lead to the formation of \( \mathrm{NO}_{2} \). **In summary:** Most collisions between \( \mathrm{NO} \) and \( \mathrm{NO}_{3} \) molecules do not result in a reaction because they either do not provide enough energy to overcome the activation barrier or do not occur with the proper molecular orientation required for the formation of \( \mathrm{NO}_{2} \). Because only collisions with sufficient energy and the right orientation lead to product formation, most NO and NO₃ molecules collide without having the necessary energy or alignment to overcome the activation barrier and react.