introduction
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Mr. Quinn & Ms. Tom March 4, 2014 Aim: How does the temperature of water change as energy is transferred? Do Now:. Introduction. This is the equation to use for all heating and cooling liquid water problems: Q = mC ( t f -t i ) - PowerPoint PPT PresentationTRANSCRIPT
Mr. Quinn & Ms. Tom March 4, 2014
Aim: How does the temperature of water change as energy is transferred?
Do Now:
What are the units for heat?
What are the units for mass?
What are the units for temperature?
What is the specific heat of water?
Introduction
This is the equation to use for all heating and cooling liquid water problems:
• Q = mC(tf-ti)
• We need to be able to get any variable by itself:Mass tf ti
Let’s Try It Out!
What is the amount of heat energy released when 20.0 grams of water is cooled from 20.0°C to 10.0°C?
Q = mC(tf-ti)
Q =m =C =tf =ti =
Hints:What are you looking for?Where do you find “C?”The temperature you start from is ti
The temperature you go to is tf
Let’s Try It Out!
The temperature of a sample of water changes from 5°C to 25°C when the sample absorbs 836 joules of heat. What is the mass of the sample?
Q = mC(tf-ti)
Q =m =C =tf =ti =
Hints:What are you looking for?Where do you find “C?”The temperature you start from is ti
The temperature you go to is tf
Let’s Try It Out!
An 8.0-gram sample of H2O (ℓ) at 9.0°C absorbs 200 joules of heat. What is the final temperature of the H2O (ℓ) sample?
Q = mC(tf-ti)
Q =m =C =tf =ti =
Hints:What are you looking for?Where do you find “C?”The temperature you start from is ti
The temperature you go to is tf
Your Turn!
Let’s Try It Out!
A 20.0-gram sample of H2O (ℓ) at 8.0°C absorbs 413 joules of heat. What is the final temperature of the H2O (ℓ) sample?
Q = mC(tf-ti)
Q =m =C =tf =ti =
Hints:What are you looking for?Where do you find “C?”The temperature you start from is ti
The temperature you go to is tf
Let’s Try It Out!
The temperature of a sample of water changes from 20°C to 40°C when the sample absorbs 836 joules of heat. What is the mass of the sample?
Q = mC(tf-ti)
Q =m =C =tf =ti =
Let’s Try It Out!
What is the amount of heat energy released when 100.0 grams of water is cooled from 30.0°C to 10.0°C?
Q =m =C =tf =ti =