Thermochemistry 1
January 28 & 29, 2013
Ms. Boon Chemistry

Take out your flashcards
please.
Catalyst
 Objectives
• Catalyst: Review your grade report.
 I can describe temperature
• List the standards in which you have
and heat flow in terms of the
earned a 3 or 4.
motion of molecules or atoms
 I can categorize chemical
• List the standards in which you have
reactions and phase changes
earned a 1 or 2.
as exothermic or endothermic.
• Did you do your homework during the
acids/bases unit?
• How much time did you spend studying
 Agenda
for the acid/base exam?
 Catalyst
• Did you complete the pH foldable
 Unit 8 Vocabulary Practice
worksheet (all sides) so that you had as
much information as possible going into
 Notes: Thermochemistry
the exam?
 Practice: Exothermic vs.
• What will help you do even better next
Endothermic
time?
Tonight’s HW: pp. 38-45; pp. 45 # 1-5, 11, 13
Shout Outs!
• Period 3:
• 3 or 4 on all standards: Douglas, Chris, Billy,
Michael
• 3 or 4 on 4/5 standards: Jeric & Irma
• Out of 27 students who have taken the test, 6
scored proficient or advanced: 22%
proficiency
Shout Outs!
• Period 5:
• 3 or 4 on all standards: Brian M., Jonathan,
Raven, Xochilt
• 3 or 4 on 4/5 standards: Cristian, Victor,
Surmani
• Out of 28 students who have taken the test, 7
scored proficient or advanced: 25%
proficiency
Shout Outs!
• Period 2:
• 3 or 4 on all standards: Tania, Rumaldo, Zamir,
Christian
• 3 or 4 on 4/5 standards: Susan, Erick, Saydy,
Rudy, Denise
• Out of 23 students who have taken the test, 9
scored proficient or advanced: 39%
proficiency
Shout Outs!
• Period 4:
• 3 or 4 on all standards: Leslie, Kieman, Patrick,
Abel, Antonio, Luis, Briceida
• 3 or 4 on 4/5 standards: Ilsse, Richard
• Out of 24 students who have taken the test, 9
scored proficient or advanced: 38%
proficiency
Shout Outs!
• Period 6:
• 3 or 4 on all standards: Kathy A., Juan,
Kimberly, Christine
• 3 or 4 on 4/5 standards: Karim, Kevin, Jahmia,
Deya, Sabrina, Sereno
• Out of 22 students who have taken the test,
10 scored proficient or advanced: 45%
proficiency
Unit 8 Introduction Videos
• http://studyjams.scholastic.com/studyjams/jams/scien
ce/matter/energy-and-matter.htm
• http://studyjams.scholastic.com/studyjams/jams/scien
ce/energy-light-sound/heat.htm
• http://studyjams.scholastic.com/studyjams/jams/scien
ce/matter/changes-of-matter.htm
• http://studyjams.scholastic.com/studyjams/jams/scien
ce/matter/solids-liquids-gases.htm
• http://teachertube.com/viewVideo.php?video_id=536
• http://www.watchknowlearn.org/Video.aspx?VideoID=
39392&CategoryID=2497
Unit 8 Vocabulary Practice
• Your partner for this activity is the person
sitting next to you.
• Materials:
– Each pair needs a white board, flashcards, and
marker.
• Rules:
– I will post a question on the board and you will
use your flashcards to answer on the whiteboard.
– Hold the whiteboard up when time is up.
Question 1
• What is the difference between heat and
temperature?
• Answer:
– Temperature is a measure of the average kinetic
energy of the particles in an object. Heat is the
energy transferred between objects because of
their different temperatures.
Next Question: List the names of phase changes from solid to liquid
and from liquid to gas.
Question 2
• List the names of phase changes from solid to
liquid and from liquid to gas.
• Answer:
– Solid to liquid: melting or fusion
– Liquid to gas: evaporation or vaporization
Next Question: List the names of phase changes from gas to liquid and from liquid to
solid.
Question 3
• List the names of phase changes from gas to
liquid and from liquid to solid.
• Answer:
– gas to liquid: condensation
– Liquid to solid: freezing
Next Question: Draw a picture of the particles in a substance as a solid, liquid, and gas.
Which has the highest temperature? How do you know?
Question 4
• Draw a picture of the particles in a substance as a
solid, liquid, and gas. Which has the highest
temperature? How do you know?
• Answer:
• The gas has the highest temperature because the
particles are moving the fastest.
Next Question: What are the two units of temperature we use in chemistry? What are
the two units for measuring heat & energy?
Question 5
• What are the two units of temperature we use
in chemistry? What are the two units for
measuring heat & energy?
• Answer:
– We use Celsius and Kelvin to measure
temperature.
– We use joules and calories for measuring heat and
energy.
That was the last question. Next up: Notes
Notes: Thermodynamics
• Thermodynamics is the branch of science
concerned with the energy changes that
accompany chemical and physical changes.
• In this unit, we will study how energy is
transferred as heat in both chemical reactions
and physical phase changes.
• Heat is the energy that transfers from one
object to another due to a difference in
temperature.
• Heat flows from HIGH to LOW temperatures
Endothermic vs. Exothermic
• Energy transfers can be categorized as either
endothermic or exothermic.
Endothermic
•In an endothermic process, energy is
absorbed.
Example: cold pack
NH4NO3(s) + H2O(l) + energy 
NH4NO3(aq)
Exothermic
•In an exothermic process, energy is
released.
Example: Hand warmer
4Fe(s) + 3O2(g)  2Fe2O3(s) + energy
•Why does the hand warmer feel hot?
•Why does the cold pack feel cold?
The energy absorbed as heat from the
surroundings makes it feel cold.
•The energy released as heat to the
surroundings makes it feel hot.
Endothermic vs. Exothermic
Endothermic
Exothermic
•Example chemical reaction equations:
•Example chemical reaction equations:
NaCl(s) + H2O(l) + energy  NaCl(aq)
KBr(aq) + AgNO3  AgBr(s) + KNO3(aq) + energy
Li2O + H2O + 365 kJ/mol → 2 LiOH
1 H3PO4 + 5 HCl → 1 PCl5 + 4 H2O + 554 kJ/mol
•Reaction Diagram
•Reaction Diagram
Endothermic vs. Exothermic
Endothermic
Exothermic
•Heat flow: Heat flows into the system
from the surroundings.
•Heat flow: Heat flows out of the system
into the surroundings.
•Example:
•Putting a cold pack on your elbow: heat
flows into the cold pack.
•Examples:
•A campfire burning: heat flows out of the
campfire.
Practice
•
•
•
•
Draw a picture for each of the following scenarios.
Clearly label the system and surroundings for each picture.
Draw an arrow in the direction of heat flow.
Label the Reaction as Endo or Exothermic
System: The egg
Heat flows: Into
the egg -Endothermic
Surroundings:
The pan, stove,
etc.
More Scenarios
Make a poster illustrating heat flow in one of the following scenarios, or make your
own!
• Melting an ice cube
• Making Ice cream
• Boiling water to make Ma n’ Cheese
• The potential energy in a bond between two atoms is released
• Mixing Calcium Chloride in water feels warm
• Iron Rusting in acid releasing steam
• Mixing baking soda in water drops the temperature slightly
• Mixing water with acid feels hot
• Condensing steam into liquid water
• Combustion of octane gas in a car’s engine
• Breaking a bond between 2 atoms during digestion takes energy
• Sweat evaporating off an athlete’s skin
• Cooking an egg
• Putting a cold pack on your knee
• Wood burning in a fireplace
• A lake freezing in the winter