a. This reaction has an activation energy of zero in the gas phase: CH3 + CH3 → C2H6. b. Why might the activation energy be zero? c. What other types of reactions would you expect to have little or no activation energy?

Verified step by step guidance

1. Understand that activation energy is the minimum energy required for a reaction to occur. In this case, the reaction CH₃ + CH₃ → C₂H₆ has an activation energy of zero, meaning it can proceed without any additional energy input.
2. Consider why the activation energy might be zero. In this reaction, two methyl radicals (CH₃) are combining to form ethane (C₂H₆). Since radicals are highly reactive due to unpaired electrons, they can readily combine without needing extra energy to overcome an energy barrier.
3. Reflect on the nature of radical reactions. Radical reactions often have low or zero activation energy because radicals are very reactive species that can easily form bonds with other radicals or molecules.
4. Think about other types of reactions that might have little or no activation energy. Reactions involving highly reactive species, such as radicals or ions, often have low activation energies because these species are eager to react and form more stable products.
5. Consider the implications of zero activation energy. Reactions with zero activation energy can occur spontaneously at any temperature, as there is no energy barrier to overcome. This can lead to rapid reaction rates under the right conditions.