chapter twelve (the other half…)
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Chapter Twelve (the other half…). Temperature & Heat. Specific Heat Capacity: Temperature Change. Specific Heat : The quantity of energy required to raise the temperature of 1 kg of a substance by 1° C. Different for each substance C water = 4186 J/ Kg·°C. - PowerPoint PPT PresentationTRANSCRIPT
Chapter Twelve (the other half…)
TEMPERATURE & HEAT
SPECIFIC HEAT: The quantity of energy required to raise the temperature of 1 kg of a substance by 1° C.
Different for each substance
Cwater = 4186 J/Kg·°C
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Q = cmΔT
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c =Q
mΔT
SPECIFIC HEAT CAPACITY: TEMPERATURE CHANGE
CALORIMETRY: Procedure to measure energy transfer in the form of heat
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Qa = −Qb
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camaΔTa = −cbmbΔTb
Example ProblemA 115 g mass of lead at 100.0 degrees Celsius
is placed in a 220 g sample of water at 20.0 ºC . What is the final temperature reached by the two substances?
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cama (Taf −Tai) = −cbmb (Tbf −Tbi)
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4186(.22)(Tf −20) =−128(.115)(Tf −100)
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921Tf − 18400 = −14.7Tf + 1470€
camaΔTa = −cbmbΔTb
128 J/Kg °C
Energy and Temperature
SpecificHeat
SpecificHeat
SpecificHeat
LatentHeat
LatentHeat
LATENT HEAT: PHASE CHANGE
• Heat of vaporization– Liquid to gas
• Heat required to cause a PHASE CHANGE
• Heat of fusion
- Solid to Liquid
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Q=mLf
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Q = mLv
Energy and Temperature
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Q = cmΔT
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Q = mLf
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Q = cmΔT
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Q = mLv
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Q = cmΔT
BOAT FIRE PROBLEM…• How much energy is required to
elevate the temperature of a 1000 gallons of water from 60° F to 212° F and then to vaporize it to steam?
1 Gallon = 0.00379 m
Boat Problem
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Q = cmΔT
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Q = mLv
How much energy is required to elevate the temperature of a 1000 gallons of water from 60° F to 212° F and then to vaporize it to steam?1 Gallon = 0.00379 m