ShmoopTube

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Here’s your Shmoop du jour, brought to you by the scientific Time Warp. [Clock ticks rapidly forward]

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It's just a shift to the left, and then a shift to the right.

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Okay, enough Time Warping…here’s our question:

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Consider the following chemical reaction equation…

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Using this equation, if we removed the entire D product from the reaction, what can we expect

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to see with regard to the current stage of this reaction?

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And here are the potential answers:

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To solve this problem, we need to remember Le Châtelier's Principal. [Person photographing men on stage]

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Thank you, 1860s French high school principal Monsieur Talbert.

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We know Henri Louis Le Châtelier couldn’t have [Henri working in a lab]

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developed his chemical equilibrium law without the nurturing school environment you helped

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to create for him.

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Bravo.

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Now that that’s out of the way, we also need to remember Le Châtelier's Principle

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of chemical equilibrium, it says that when a chemical system in dynamic equilibrium is [Teacher writing on the board]

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perturbed by changing the conditions, the equilibrium changes to counteract the perturbation.

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In our chemical reaction, if we remove all of the product D, then Le Châtelier's Principle [Product D removed from chemical reaction]

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tells us that the reaction will adjust to counteract that change by creating more of

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the product D.

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This would correspond to the reaction proceeding from left to right. [Blue ball moves from left to the right]

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It’s kind of like a clown car packed with clowns.

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…Which…come to think of it, really can’t be safe. [Clowns enters small car and drives away]

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But anyway.

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If all the clowns in the back seat get out, some of the other clowns will move to the

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back so the driver can see the road.

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…Seriously, how have police not cracked down on this yet?

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Here’s another way to think about it.

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If our chemical reaction is at dynamic equilibrium, the rate of the forward reaction is exactly

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the same as the rate of the reverse reaction. [D reactants in the woods covered in barbed wire]

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If all of species D were removed, the forward reaction could still proceed at the same rate,

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but the backward reaction could not take place at all since there would be no D available

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to react.

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As a result, the overall net reaction would proceed from left to right.

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So, we can see that the reaction will move from left to right.

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Another way to say the same thing is that the equilibrium will shift to the right.

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This just happens to be answer choice (A), which is the right answer. [Answer A circled green]

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And now if you'd excuse us, we have a few citizens' arrests to make. [Police arresting man riding scooter]

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Keeping the roads safe, one clown car at a time.

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