Factors affecting reaction rate.
Use collision theory to explain.
Factor: nature of the reactant
Affect on rate: more or less reactive based on its chemical identity.
reactivity:
aq>g>l>s
Explanation:
For the other factors, we had to explain it based on whether the factor helped the collisions have sufficient energy or have correct orientation.
For "nature of the reactant", I'm not too sure how to explain. For example, I could say if a chemical is aqueous, then it's just free-floating ions in solution so the bonds are already broken. This could increase the reaction rate because it has lots of energy but I also think it could be because since they're free-floating ions, there's more chance of colliding with correct orientation??
Same with gases; lots of energy, and they're floating around...
Solids have low energy and they don't move that much...?
I don't know.
Also, for catalysts, what would the explanation be based on collision theory?
I know catalysts "increase the rate of the reaction by providing an alternate reaction pathway, increasing the number of successful collisions"
but does it increase the number of successful collisions by providing sufficient energy to the particles or by increasing the chance of collisions with correct orientation (like for surface area, smaller particles result in more collisions with correct orientation)...?
For the catalyst, the rate is increased because the activation energy barrier is lowered (that's the alternate path) so more particles with the right energy can meet(collide) and react.
Factors affecting reaction rate can be explained using collision theory. Collision theory states that for a reaction to occur, particles must collide with sufficient energy and proper orientation.
1. Nature of the Reactant: The nature of the reactant can influence the reaction rate. In collision theory, we consider the different phases of matter: aqueous (aq), gas (g), liquid (l), and solid (s).
- Aqueous reactants: In solutions where the reactants are dissolved in water, the bonds between the reactant molecules are already broken, and the particles are free-floating ions. This means they have more energy and are more likely to collide, increasing the chance of successful collisions and, hence, the reaction rate.
- Gaseous reactants: Gas particles are highly energetic and in constant motion. They have sufficient energy and are more likely to collide with other particles, resulting in more frequent collisions and a higher reaction rate.
- Liquid reactants: In liquid reactions, the particles are closer together compared to gases but can still move freely. The rate might be slower compared to gases due to less frequent collisions, but the energy of the particles might still be sufficient to overcome the necessary activation energy barrier.
- Solid reactants: Solid reactants have low energy and limited mobility. As a result, the rate of reactions involving solids tends to be slower compared to reactions involving gases or liquids. The limited movement restricts the frequency of collisions, which lowers the reaction rate.
It's important to note that the explanation based on collision theory can encompass both the increased energy and the increased chance of collisions with proper orientation. The different phases of reactants affect the availability of energy and the mobility of the particles, influencing the reaction rate accordingly.
Regarding catalysts, collision theory explains how they increase the reaction rate by providing an alternate reaction pathway and increasing the number of successful collisions. Catalysts work by lowering the activation energy required for the reaction to occur. This decrease in activation energy allows a higher proportion of the reactant particles to have sufficient energy to overcome the barrier. Consequently, more successful collisions can occur between reacting particles, leading to an overall increase in the rate of the reaction. Therefore, catalysts primarily increase the number of successful collisions by lowering the activation energy rather than influencing the orientation of collisions.