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Specific Heat Capacity of water

  1. Oct 2, 2014 #1
    The specific heat capacity of water is accepted to be roughly 4.18 J/gK. How would the specific heat value of a given water sample be effected when sediments and other forms of particulation, such as iron oxide from rust, are present? Would the mixture have a higher specific heat capacity value compared to pure water and thus require more energy to satisfy the same delta T?

    Thoughts and any insight will be much appreciated.
  2. jcsd
  3. Oct 2, 2014 #2


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    Well, what would you think would happen?
  4. Oct 2, 2014 #3
    The heat capacity of iron oxide is much lower than water. So, the heat capacity of the mixtures of water and iron oxide would be less than water alone.

  5. Oct 4, 2014 #4
    I would expect the dirty water to be a less efficient heat transfer medium and therefore have a higher specific heat. But, let's say I had 10g of pure water as sample A and 10g of dirty water (a mixture of sediments and iron oxides) as sample B, of that 10g the particulates account for .5g of the total weight. Sample A would have a SH of roughly 4.18 while sample B would have a SH value of 4.18 for 9.5g of the mixture and a value "c" for the .5g of particulates with c being less than the value of water. When I look at the situation this way I believe the dirty water would have a lower SH. However, I also wonder on a molecular level if the particulates which are in suspension, play a role in how heat is transferred through conduction. Meaning do they, the particulates, interfere with how well heat is transferred to the surrounding water.
  6. Oct 4, 2014 #5

    Chet, see my second post above. Do you believe my thought process is correct? I guess I'm asking, is you're statement based of a similar thought process of mine? And what would you have to say about my last portion with the particulates being in suspension and perhaps effecting how well heat is transferred to the mixture through conduction?
  7. Oct 4, 2014 #6


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    The specific heat capacity of water will probably have been measured using a rig that stirs the water to eliminate any error due to conduction. In any case good thermal conductivity just helps ensure uniform temperature. It doesn't/wouldn't change the energy required to raise the temperature.
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