Indicate the order of reaction consistent with each observation.
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Question

Indicate the order of reaction consistent with each observation.
a. The half-life of the reaction gets shorter as the initial concentration is increased.

Accepted Answer

Hey everyone in this example, we need to determine the order of a reaction. For reaction with a half life that decreases as the initial concentration increases. So what we should recall is our half life calculation for a second order kinetic reaction. And we should recall that that formula is equal to one divided by the rate constant K. Multiplied by our initial concentration of our reactant. And so we would see that because half life is in the numerator and our initial concentration of our reactant is in the denominator. We would say that half life has an inverse relationship with our initial concentration. And so we would say that therefore if we increase our half life we would therefore decrease our initial concentration of our reactant. And likewise, if we decrease half life we would increase our initial concentration of our reactant. And so according to the prompt, we would confirm that the correct answer choice is going to be choice C which states that the reaction is going to be second order. Because we have outlined the formula for calculating the half life of a second order reaction. And we saw the inverse relationship between half life and our initial concentration of our reactant. So if you have any questions, just leave them down below. Otherwise I will see everyone in the next practice video

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