b. As the temperature increases, does the reaction rate usually increase or decrease?

Video transcript

Hey everyone today, we're being asked how the rate of a chemical reaction changes when the temperature is decreased. Now there are two ways in which we could think about this one theoretical and one is a little more mathematical, let's take a look at the theoretical explanation. First. Assume we have, let's say we have a container and we have a few particles in here. Some reactant. Let's say we know that temperature temperature is a measure of kinetic energy or the average kinetic energy of a substance or of a particle or anything like that. So as temperature decreases, the kinetic energy of the molecules will also decrease. As this decreases. One will also decrease their directly proportional. And when kinetic energy of molecules decreases, that means they move around less. They're less likely to bounce off of walls or bounce off the walls of the container and collide with each other and we know that for a reaction to take place, collisions between the molecules is essential for the reaction to proceed. So if kinetic energy decreases and there's less bouncing, less energy, less collision, that means the rate would also decrease, the rate decreases. So as the temperature decreases, so too does the rate of the reaction. However, I'd like to take a look at a slightly more mathematical approach, let's take a look at the Iranians equation, which tastes at the rate constant is equal to the area. Oops, multiplied by e to the power of negative a over R. T. Now we know this formula, but what we're concerned about here is this factor right here, the T. Which stands for temperature now assuming everything else remains constant within the reaction. If we decrease the temperature, excuse me. If we decrease the temperature here that will make the denominator bigger. So our T. Oh sorry. As we increase the temperature that would make the denominator or decrease the temperature. That would make the denominator smaller. That's it becomes smaller. Which means this overall term, this exponents itself would become a larger value. And as a negative exponent becomes larger. That means the final answer will be smaller as well. So that means as temperature decreases so too does the rate constant as such. The rate constant is directly proportional to the rate of the reaction. So if the rate constant decreases that means the rate of the reaction also decreases. I hope this helps. And I look forward to seeing you all in the next one.