jewels
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chemistry word problem
How many calories are required to raise the temperature of 225g of water from 42C to 75C ?
Thanks to all
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Mephisto
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(1) Q [in joules] = mass of the water <b>·</b> heat capacity of water [g] (= 4.18 J <b>·</b>
K<sup>-1</sup> <b>·</b> g<sup>-1</sup> <b>·</b> <font face="symbol">D</font>T
(2) 1 J = 0,238 cal
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Mr. Wizard
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A calorie will raise one gram of water one degree C. So if you have 225 grams it will take 225 calories to raise it from 42C to 43C. Since there are
33 steps (75-42) you multiply 225 x 33 =7425 calories. Water actually slightly changes it's 'heat capacity' or Specific Heat as it
changes temperature. A specific heat of 1.0 is used for this calculation. Water's specific heat of 1.0 is actually quite high.
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