For each reaction, estimate whether
ΔS° for the reaction is posi...

Question

For each reaction, estimate whether ΔS° for the reaction is positive, negative, or impossible to predict. a. N-decane

heat catalyst —> Propene

+ heptane

(catalytic cracking)

Accepted Answer

Welcome back, everyone predict the sign of delta S for the following reaction where N on Decca reacts with a catalyst and is placed under high heat to form two products, protein and N octane. So what we go from is one mole of a reactant to form two moles of products. And we want to recall first that delta S represents entropy or entropy change for our system, which we want to recall describes the disorder or randomness of a system. And it also refers to the tendency of a system to take its most probable form where it's going to always go with the form of more disorder. And because we see that we have two moles of two different products, we have more disorder on the product side of the reaction. We also want to recognize that this is due to the fact that our reactant is placed under high heat conditions. And so as its temperature is raised, the bonds of this reactant break to form our two products. Here, we want to recall that entropy change will increase along with greater freedom of motion. And so even though we also have more randomness on the product side, we also want to recognize that this randomness is also attributed to the greater range of motion each of these products have versus just the range of motion of one mole of our reactant and, and decking. And so we would confirm that the sign of entropy is going to be positive since in the reaction, one more of the reactant and becomes two smaller molecules with greater freedom of motion. So this is going to correspond to choice C and the multiple choice as our final answer to complete this example, as the sign of entropy for the reaction being a positive sign, I hope everything I reviewed was clear. If you have any questions, please leave them down below and I'll see everyone in the next practice video.

For each reaction, estimate whether ΔS° for the reaction is positive, negative, or impossible to predict. a. N-decane heat catalyst —> Propene + heptane (catalytic cracking)

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For each reaction, estimate whether ΔS° for the reaction is positive, negative, or impossible to predict. a. N-decane
heat catalyst —> Propene
+ heptane
(catalytic cracking)