Answer Key: Self-Test C-1.19
- Define specific heat.
- Specific heat is the amount of heat necessary to raise the temperature of 1 lb. of a substance 1 °F.
- Define sensible heat.
- Sensible heat is the heat energy gain or loss that will cause the temperature of a substance to change.
- Define latent heat.
- Latent heat is the heat energy gain or loss that will cause the physical state of a substance to change.
- Give the BTU values for the following:
- specific heat for ice
- [latex]0.5\frac{\text{BTU}}{\text{lb.}}\text{°F}[/latex]
- specific heat for water
- [latex]1\frac{\text{BTU}}{\text{lb.}}\text{°F}[/latex]
- specific heat for steam
- [latex]0.5\frac{\text{BTU}}{\text{lb.}}\text{°F}[/latex]
- latent heat of fusion (water)
- [latex]144\frac{\text{BTU}}{\text{lb.}}[/latex]
- latent heat of vaporization (water)
- [latex]970\frac{\text{BTU}}{\text{lb.}}[/latex]
- specific heat for ice
- How many BTUs are required to raise the temperature of 39 pounds of water at 47°F to water at 212°F?
- 6,435 BTU
- How many BTUs are required to raise the temperature of 17 lb. of ice at 3°F to water at 79°F?
- 3,493.5 BTU
- How many BTUs are required to raise the temperature of 23 imperial gallons of water at 150°F to steam at 225°F?
- 238,855 BTU
- How many BTUs are liberated when 183 pounds of steam are cooled from 250°F to –18°F ice?
- 244,854 BTU
- How many pounds of ice at 12°F could we change to water at 121°F if we introduced 145,000 BTU to the container?
- 597 lb.
- How many BTUs will it take to heat 4,124 lb. of ice at –17°F to steam at 233°F?
- 5,480,796 BTU
- How many pounds of steam at 245°F could we change to ice at –77°F if we removed 900,500 BTUs from the substance?
- 659.7 lb.
- How many BTUs would it take to heat 256 lb. of ice at –55°F to steam at 259°F?
- 348,416 BTU
- How many BTUs would it take to warm up a swimming pool by 20°F if the pool measured [latex]16\text{'} \times 20\text{'}[/latex] and had an average depth of 5′?
- 1,996,800 BTU
- How many BTUs would it take to warm up a hot tub by 25°F if the tub measured 6′ in diameter and had a depth of 4′?
- 176,432 BTU