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Specific heat units

  1. Oct 30, 2011 #1
    Hopefully this is a really simple question to answer. A problem I have uses the following information:

    The specific heat of air = 1.05 kJ/hg-C.

    Does anyone know what the hg-C stands for? I know specific heat is usually expressed in terms of J/C, so this is confusing me.
  2. jcsd
  3. Oct 30, 2011 #2
    The units of specific heat are energy per unit of mass per unit of temperature. Thus it should read kJ/(kg C). I think you misread the unit and ended up with hg instead of kg.
  4. Oct 30, 2011 #3
    Nope, I double checked and the units are definitely kJ/(hg-C). Any ideas as to what the hg may be? Is it some reference to mercury?
  5. Oct 30, 2011 #4
    It doesn't refer to mercury. Let's say it's a typing mistake. I stand by my previous post
  6. Oct 30, 2011 #5
    The specific heat of air is of the order of 1 kJ/kg.K (or kJ/kg.C). The exact value depends on temperature. So it is a typo, no doubt.
    The units J/C (asuming C stands for Celsius degree) are for heat capacity and not for specific heat.
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