Do Now

On your Daily Organizer, answer the following
questions under Do Now.
 Define
specific heat capacity.
 If one object has a greater specific heat capacity than
another object, what does that tell you about it?
 Based on yesterday’s balloon demo, what happens to
the molecules of an object when they are heated up?
Today’s Agenda
5 min
• Do Now
5 min
• Important Dates
10 min
• Specific Heat
35 min
• Quantity of Heat
5 min
• Exit Ticket
Today’s Agenda
5 min
• Do Now
5 min
• Important Dates
10 min
• Specific Heat
35 min
• Quantity of Heat
5 min
• Exit Ticket
Important Dates & Reminders

Quiz Tomorrow
5



multiple choice questions over temperature & heat
Lab Notebooks Due Next Friday
Grade Notices Monday
Homecoming Activities
Today’s Agenda
5 min
• Do Now
5 min
• Important Dates
10 min
• Specific Heat
35 min
• Quantity of Heat
5 min
• Exit Ticket
Temperature vs. Heat
Temperature

Measure of the
hotness/coldness and
the kinetic energy
Heat

Transfer of energy
from hot object to cold
object
Specific Heat


Different substances have different abilities to store
energy.
The specific heat of a substance is defined as the
quantity of heat required to change the
temperature of a unit of mass (like a gram or
kilogram) of the substance by 1 degree.
 Metric
Units: Joules/kilogram*Kelvin (J/kg*K).
 More commonly used units: J/g*°C.
Check for Understanding

Water has a specific heat capacity of 4.18 J/g*C.
Vegetable oil has a specific heat capacity of of
0.67 J/g*C.
 Which
one has a greater specific heat capacity?
 What does that tell you about water vs. oil?
Check for Understanding

The specific heat capacity of gold is 0.129 J/g*C.
The specific heat capacity of diamond is 0.509
J/g*C.
 If
both start out at the same temperature, which one
would be easier to melt? How do you know?
Check for Understanding

Water has an unusually high specific heat capacity.
Which one of the following statements can we say
knowing that fact?
A.
B.
C.
Compared to other substances, hot water causes bad
burns because it is a good conductor of heat
Compared to other substances, water will quickly
warm up to high temperatures when heated.
Compared to other substances, it takes much more
heat for a sample of water to change its temperature
by a small amount.
Today’s Agenda
5 min
• Do Now
5 min
• Important Dates
10 min
• Specific Heat
35 min
• Quantity of Heat
5 min
• Exit Ticket
Calculating Energy


We can find the amount of thermal energy gained
or lost by any substance by using its specific heat
capacity, the mass of the substance and the
temperature change.
Q = mcΔT
 Positive
Q: object gained energy – there was an
increase in temperature (heated up)
 Negative Q: object lost energy – there was a decrease
in temperature (cooled down)
Calorimetry
Calorimetry is the science associated with
determining the changes in energy of a system
by measuring the heat exchanged with the
surroundings.
A calorimeter measures the amount of heat
transferred.
Check for Understanding
Situation
An ice cube is placed into a glass of room
temperature lemonade in order to cool
the beverage down.
A cold glass of lemonade sits on the
picnic table in the hot afternoon sun and
warms up to 32°F.
The burners on an electric stove are
turned off and gradually cool down to
room temperature.
Heat Gained Q: + or or Lost
Check for Understanding
Situation
Heat Gained Q: + or or Lost
An ice cube is placed into a glass of
room temperature lemonade in order to
cool the beverage down.
Gained
+
A cold glass of lemonade sits on the
picnic table in the hot afternoon sun and
warms up to 32°F.
Gained
+
The burners on an electric stove are
turned off and gradually cool down to
room temperature.
Lost
-
Example Problem: Finding Q

How much heat is needed to raise the temperature
of 350 grams of water from 10.0°C to 25°C? The
specific heat capacity of water is 4.18 J/g/°C.
Practice Problem

A 100-gram sample of water is heated from 18°C
to 32°C. Determine Q. The specific heat capacity of
water is 4.18 J/g/°C.
Example Problem: Finding m

A sample of water loses 175 Joules of heat when it
cools from 55°C to 30°C. What is the mass of the
water sample? The specific heat capacity of water
is 4.18 J/g/°C.
Practice Problem

A sample of aluminum gains 95 Joules of heat when
it heats up from 30°C to 50°C. What is the mass of
the water sample? The specific heat capacity of
water is 0.904 J/g/°C.
Example Problem: Finding c

An unknown metal gained 150 J of heat when it
had a mass of 65 g increase in temperature from
48 °C to 89 °C. What was the specific heat
capacity of the unknown metal?
Practice Problem

An unknown substance with a mass of 80 g lost 145
J of heat energy when its temperature decreased
from 95 °C to 75 °C. What was the specific heat
capacity of the unknown substance?
Challenge Problem

A 25 gram piece of metal with a temperature of
75°C is placed in a calorimeter that holds 50.0 g of
water. If the heat energy produced was 290 J,
what was the initial temperature of the metal?
Independent Practice
Complete the three independent practice
problems before getting checked and doing
your exit ticket.
Today’s Agenda
5 min
• Do Now
5 min
• Important Dates
10 min
• Specific Heat
35 min
• Quantity of Heat
5 min
• Exit Ticket