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Chemistry help please !!

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4mica
Posts: 1017 - Karma: 60
How many joules are required to heat 692g of nickel from 22c to 318c ?                 

    it gives me the formula  Q= (mass) (change in temp) (specific heat)     

  but i used that and got 90,126.08   which seems way to huge

seriously any help is appreciated ... i wasn't there when she went over this stuff
Feb 17 2008 10:36PM
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JaphyRyder
Posts: 1766 - Karma: 113
eh, try mass in kg instead of g, so 0.692 kg. I think thats whats supposed to go in to that equation
Feb 17 2008 10:45PM
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anxju
Posts: 9371 - Karma: 61
Q=MC delta T

q is in joules
mass is in g
c is the specific heat of the thing
t is the change in temp
Feb 17 2008 10:57PM
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popNfresh44
Posts: 3757 - Karma: 44
i used to be able to do that exact type of question...

but that was 2 units ago
Feb 18 2008 10:39AM
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GatoGordo
Posts: 1496 - Karma: 10
It is 90,126.08 joules. It makes sense, because you have to raise the temp by a lot, so you would need that many joules.
Feb 18 2008 10:50AM
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2814
Posts: 292 - Karma: 10
I got 90945.408


Energy Required = M x deltaT x HC
 '                '         = .692kg x 296C x 444J
                           = 90945.408


I may be a bit rusty as I haven't taken chem in 2 years, but I think I'm right.
Feb 18 2008 11:09AM
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4mica
Posts: 1017 - Karma: 60
for reall , i really appreciated the help there guys .
Feb 18 2008 5:31PM
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rather.be.skiing
Posts: 239 - Karma: 15
change your answer into kJ too.
Feb 18 2008 6:20PM
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user098123
Posts: 6072 - Karma: 18
Ya the only reason it looks huge is because you have it in Joules. Many times, especially for specific heat related problems, it will be in kJ. 90 kJ or whatever your answer is alot by any means.
Feb 18 2008 7:18PM
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jedi.Jim
Posts: 1133 - Karma: 13
Your answer is right; it's definately going to take alot of energy to change the temperature of over a half kilo of metal.
Feb 18 2008 10:28PM
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Yauch
Posts: 1685 - Karma: 62
this man speaks the truth
Feb 18 2008 10:30PM
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