The characteristic gas constant of any gas equals______________________?
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Answer: C. Cp – Cv
Explanation
The characteristic gas constant equals the difference between specific heat at constant pressure and volume. Mayer relation mathematically proves that R equals Cp minus Cv for any ideal gas. This fundamental property links thermal heat capacities directly to the mechanical state equation of gases. Specific heat at constant pressure exceeds specific heat at constant volume because of external work done. Universal gas constant divided by the molar mass of a specific gas yields its characteristic gas constant. Ideal gas equations utilize this constant to relate pressure, volume, temperature, and mass.
Mechanical engineers use the characteristic gas constant when calculating gas expansion work in power cycles. HVAC system designs require accurate gas constant values for air and refrigerant property estimations. Thermodynamic cycle analysis relies on specific heat differences to determine internal energy changes. Dividing specific heat at constant pressure by constant volume yields the specific heat ratio gamma, not R. Inverting the specific heat ratio provides no standard thermodynamic property matching the gas constant. Adding specific heat capacities together calculates thermal storage properties rather than the gas constant.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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