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Amount of of heat required for different materials to heat.

  1. May 14, 2012 #1
    Hi I am new to this Forum as well as thermodynamics.

    I need to find the amount of heat required to change the temperature of two given materials (iron bar and sand), from 25 deg C to 120 deg C. I have two steel tanks, one for holding each material. Both the tanks have the same dimensions (1m, 1m 3m). I basically need to compare the amounts of heat required for both.

    I know that it requires mass and specific gravity of a material to compute the amount of heat along with the temperature difference and the formula is Q= m*c*ΔT

    I am not sure if it's just this or it has more calculations involved as the two materials are stored in steel tanks and hence if there are any losses or any other considerations to be made. I have found out the specific heats for both iron and sand to be 0.11 and 0.19 respectively.

    Please do help me out with any suggestion or idea as to how to go about it.

    Thank you.
  2. jcsd
  3. May 18, 2012 #2
    Get a known amount of water (say 1kg), heat it to 100 C, then combine it with an equal amount of the sand/iron. Track the temperature of the water until it stops changing.

    If you assume the only heat transfer is between the iron/snad and the water, you can calculate the heat capacity by setting the heat transfer on each side equal to each other.

    Cwater*deltaTwater = Csand*deltaTsand

    You know the starting and ending temperatures, and you know the Cwater (4.18 J/g*K), so you can solve for Csand.

    This assumes that heat capacity does not change with temperature.
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