Sensible heat taken up by 1 lb of water heated from 32 to 212°F is approximately ______________ BTU?
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Answer: A. 180
Explanation
Sensible heat is the thermal energy required to change water temperature without phase change. Multiplying water mass by its specific heat capacity and temperature rise yields approximately 180 BTU. The temperature difference between freezing and boiling points on the Fahrenheit scale is 180 degrees. Specific heat capacity of water is approximately one BTU per pound mass per degree Fahrenheit. Freezing point of water is 32 Fahrenheit and boiling point is 212 Fahrenheit at standard pressure. Sensible heat calculations require multiplying mass, specific heat, and delta T.
Steam power plant design requires calculating sensible and latent heat loads for boiler feedwater. Thermal energy storage calculations rely on accurate specific heat values for water and other fluids. Understanding BTU definitions is essential for traditional engineering thermodynamic computations. Values near 970 BTU represent the latent heat of vaporization for water, not sensible heat. Smaller numbers like 3.97 result from incorrect unit conversions or metric system confusions. Stating data is insufficient ignores well-established thermodynamic property tables for liquid water.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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