Q. Two gaseous molecules can react only when they have same _____:
Answer: orientation/ steric factor
Notes: According to the Collision Theory, a chemical reaction can occur only when the reactant molecules, atoms, or ions collide with more than a certain amount of kinetic energy and in the proper orientation. In order to effectively initiate a reaction, the reactants must be moving fast enough (with enough kinetic energy) so that they collide with sufficient force for bonds to break. This is known as the activation energy. However, even if two molecules collide with sufficient activation energy, there is no guarantee that the collision will be successful. In fact, not every collision is successful, even if molecules are moving with enough energy. The reason for this is because molecules also need to collide with the right orientation, so that the proper atoms line up with one another, and bonds can break and re-form in the necessary fashion. An effective collision is defined as one in which molecules collide with sufficient energy and proper orientation, so that a reaction occurs. For example, in the gas-phase reaction of dinitrogen oxide with nitric oxide, the oxygen end of N2O must hit the nitrogen end of NO; if either molecule is not lined up correctly, no reaction will occur upon their collision, regardless of how much energy they have.

This question is part of 40000+ General Studies MCQ Series Course on GKToday Android app. Question Number: 45 in Chemistry-11-Chemical Reactions in above course in App.