1. The two things that would determine whether a reaction would occur or not would be the orientation of the collision, or whether the reactive parts of each of the two particles come into contact with each other, and whether the reactants particles collide with sufficient kinetic energy to bring about the reaction.
2. There are different factors that can affect the rate of a chemical reaction:
a. Increasing the concentration of the reactants or the pressure of a gaseous reaction.
– As the amount of particles in a certain volume increases, the number of collisions will increase. The ratio of successful collisions to unsuccessful collisions will still be the same. However, since there are more collisions, the number of successful collisions will also increase, and therefore the rate of reactions in the bigger picture increases.
b. Increasing the temperature of the reaction
– As temperature increases, one adds more kinetic energy to all the particles of the substance, therefore increasing the number of reactant particles with the necessary activation energy. By doing so, the ratio of successful collisions to unsuccessful collisions will increase, so more collisions will be successful, thus increasing the rate of reaction.
c. Decreasing the particle size of solid reactants
– Considering a solid has a lot less kinetic energy than the other phase, it would have a more rigid shape and would not be as free-flowing to react quickly with the other reactant due to the fact that only the outside part of the solid (surface area) comes into contact with the other reactant. By breaking the solid into smaller pieces, the surface area would greatly increase, thus more solid particles are available to react. That is why if the solid is in powder form the surface area is considerable increased, and thus the rate of the reaction will be much faster.
d. Adding a suitable catalyst
– A catalyst is a substance that increases the rate of a chemical reaction without itself being changed in the process of the reaction. They work by bringing the reactant particles into close contact with one another, meaning they provide an alternative pathway with a lower activation energy. ore the reactant particles will possess this lower activation energy, and so the rate increases.
3. The Ea or the activation energy is the minimum amount of energy required to bring about a reaction. When comparing reactions with slow rates and that with faster rates, the faster rates would obviously have lower Ea since it takes a lot less energy for the faster reaction to take place, meaning the collisions of particles happen successfully a lot more, and since one criteria for a reaction to occur would be to have sufficient kinetic energy from the particles, this would allow us to infer that it takes less energy between the particles of the faster reaction to successfully collide, thus the fast reaction rate, thus requires a lower Ea than a slower reaction.
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