ShmoopTube

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And here's your Shmoop du jour, brought to you by iced tea…A refreshing drink turned

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talented rapper turned even more talented detective on Law and Order SVU. [Iced tea glass transforms from rapper to detective]

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Dun dun.

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Alright, here's today’s question.

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On a hot summer day, there is nothing like a nice, cold glass of iced tea.

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To cool iced tea, the ice cubes must melt.

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How much energy would be required to completely melt 60.0 g of ice at 0 °C?

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The heat of fusion for ice equals 6.01 kJ/mol.

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And here are your potential answers.

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All right, for the quantitative part of this problem, we need to think about water. [Person using a calculator]

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Ah, so peaceful…

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…Darn it.

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Now we need a bathroom…[Toilet flushes]

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Okay, where were we?

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Oh, yeah, science.

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Great.

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So, we're given a heat of fusion, which is the amount of energy needed to melt one mole

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of ice at 0°C.

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To calculate the amount of energy needed to melt 60 grams of ice, we have to convert this [Robot shoots a laser and melts ice cubes]

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weight to moles using the molecular weight of water.

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Now we can just multiply the number of moles of ice by the heat of fusion to calculate

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the overall heat, Q.

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This question is a great example of why units are your best friend… [Boy juggling with measurement units]

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Sorry, dogs.

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You've been demoted.

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By looking at the units of our answer and the information that we’ve got, we can deduce

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the equation that should be used.

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This is a great trick for when you’re unsure or just want to double check. [Girl scribbling in class]

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It's also just a great party trick in general…y'know, if your thing is getting uninvited to parties. [Boy at a party with 3 upside down red cups]

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Anyway, we can see that the correct answer is choice C, - 20 kJ.

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All right, Fido, you can come back now.

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We’re ready to play. [Boy shouts for Fido to come play]

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Fido?

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Where are you?

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We were just kidding about that best friend thing… [Fido on the sofa reading a newspaper]

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