ShmoopTube

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Here’s your Shmoop du jour, brought to you by lines, helping scientists get dates since

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1811. [Boy and girl looking at paintings]

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Because what's dating without a little…chemistry?

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Alright, here’s today’s question:

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A graph of which of the following data will give a straight-line graph for a first order

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reaction?

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And here are your potential answers: All right, so we know that for a first order

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reaction, the rate is proportional to the concentration of the reactant. [First order reaction equation]

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That means that as the reaction proceeds, the concentration of the reactant decreases

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more and more slowly.

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To be a little more specific, the concentration of [A] decays exponentially.

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Just like your concentration in the math class you have right before lunch. [Students in math class]

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If your eyes are in proper working order, you can tell by looking at the graph that

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this is not a straight line. [Graph with a sloping line]

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If it looks like one to you, we highly recommend a quick visit to the optometrist. [Girl conducting an eye-exam]

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Anyway, since this is a graph of the concentration of A versus time, we can eliminate A).

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Options C) and D) could be right if the reaction orders were different.

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But, unfortunately, teachers don’t give credit for potential correctness. [Answers C and D crossed out]

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So that means that a graph of B would give you a straight line for a first order reaction.

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For first-order reactions, the graph of the natural log of the concentration of the reactant

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versus time will be a straight line.

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So B will take you straight to the finish line. [B crossing the finish line on a running track]

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We’d tell you another chemistry pick up line, but all the good ones argon. [Periodic table and Argon asks to call me]

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