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A biology experiment requires the preparation of a water bath at 37 degrees celsius.
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The temperature of the cold water is 22 degrees celsius and the temperature of the hot water is 55 degrees celsius.
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If a student starts with 90 grams of cold water, what mass of hot water must be added to reach 37 degrees celsius? so we're going to look at the cold and the hot.
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We use the equation q equals mc delta t.
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So the heat equals the mass times specific heat times the change in temperature.
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For our cold water, our change in temperature, our final temperature is 37 .0 minus the 22 and that equals 15 degrees celsius.
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So that's our change in temperature.
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Let's do the same thing for the hot.
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For the hot, our delta t is going to be 37 degrees celsius and it goes from 55 degrees celsius so our change in temperature is negative 18 degrees celsius.
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So what we want is we know that our end temperature, the heat lost by the hot water and the heat gained by the cold water has to be the same.
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But they're going to be in opposite signs because one is lost and the other is gained.
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So that means our q cold is going to be the negative of q hot...