Chemical Reactions: Combustion Reactions (Day 2 of 5)
Name:
Grade Level:
School:
Date:
Time:
Cody VanRosendale
11
Brookings High School
9/28/15
10:05
Reflections from Last Lesson: The last lesson was the introduction to the unit. Students learned about
stoichiometry and balancing equations. After I explained how to balance equations, students practiced on
their own and did examples on the board as a class. The majority of students seemed to have a grasp on
the topic.
Contextual factors/learner characteristics:
Standards Addressed HS-PS1-2
Performance Expectation
Science and Engineering
Practice
Disciplinary Core Idea
Crosscutting Concepts
CCSS ELA / Math
Construct and revise an explanation for the outcome of a simple
chemical reaction based on the outermost electron states of
atoms, trends in the periodic table, and knowledge of the
patterns of chemical properties.
Construct and revise an explanation based on valid and reliable
evidence obtained from a variety of sources (including students’
own investigations, models, theories, simulations, peer review)
and the assumption that theories and laws that describe the
natural world operate today as they did in the past and will
continue to do so in the future.
The fact that atoms are conserved, together with knowledge of
the chemical properties of the elements involved, can be used to
describe and predict chemical reactions.
Different patterns may be observed at each of the scales at which
a system is studied and can provide evidence for causality in
explanations of phenomena.
Develop and strengthen writing as needed by planning, revising,
editing, rewriting, or trying a new approach, focusing on
addressing what is most significant for a specific purpose and
audience.
Choose a level of accuracy appropriate to limitations on
measurement when reporting quantities.
Objectives: Chemistry students will be able to balance combustion equations with 95% accuracy.
Chemistry students will be able to list four essential component of an organic
combustion reaction with 100% accuracy.
I can statements: At the end of the class, I can balance combustion reaction and will know the four
essential molecules that are involved in organic combustion reactions.
Materials and Resources needed: Textbook and white boards for the students to write on.
The Lesson – For this lesson, I will start off by showing a demonstration of a combustion reaction like
the ‘genie in a bottle’ using isopropyl or by using the popular firework snakes. I will already have the
demonstration prepared when students come in and I will explain what is happening as the demonstration
is going on. After the demonstration I will share the objective for the day and give them a few equations
to balance to gauge what they retained from the last lesson. After a few individual and class problems I
will continue on by explaining what combustion reactions are and how we know it is a combustion
reaction. I will go into detail about why carbon, hydrogen and oxygen react so well with each other to
create combustion reactions and its products. We will do a few more problems as a class and then as
individuals. I will show a video demonstration of how a combustion engine works and explain what is
happening in the combustion reaction, then I will have them balance the equation for the reaction that is
taking place and write a short summary of how an engine burns fuel. Before students leave I will have
them fill out an exit slip in which they have to list the four molecules present in an organic combustion
reaction.
1. Introduction (Engage)
Getting attention (3 min)
Relating to past experience
and/or knowledge (10 min.)
Sharing objective, in
general terms (1 min)
Genie in a Bottle demonstration
Balancing equations
Today we are going to learn about combustion reactions, how to
balance them and the four things that are present in all organic
combustion reactions.
2. Methods (core of the lesson)
What you are
doing /
Methodology
(time allotment)
Lecture(15)
-What general rules about balancing equations did we learn last class
period?
-Why do you think that a camp needs to have air in order to stay lit?
-Explain that a combustion reaction needs: hydrocarbon, O2 and produces
water, CO2 and heat making it an exothermic reaction
-Explain that there are complete and incomplete reactions. Incomplete
reaction the O2 is limiting reactant. In complete reactions there is enough
O2 to completely use up the entire hydrocarbon to produce CO2.
-Show examples of complete CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) and
incomplete CH4(g) + O2(g) → C(s) + 2H2O(g)
Generic combustion C4H6O3 + H2O −−→ C2H4O2
reaction
problems(5)
Engine
Demonstration(5)
Engine reaction
equation/short
answer(5)
C4H10O+ O2 −−→ CO2 + H2O
FeBr3 + H2 SO4 −−→ Fe2 (SO4 ) 3 + HBr
7H9 + HNO3 −−→ C7H6 (NO2 ) 3 + H2O
C5H8O2 + NaH+ HCl −−→ C5H12O2 + NaCl
- https://www.youtube.com/watch?v=bLXDPs7UrXs
-The gas enters in to the cylinder as the air and both are composed so that
the sparking of the mixture pushes the pistons down and drives the crank
shaft. The spark is the catalyst in this reaction.
-Chemical formula for gas(isooctane) C8H18
3. Back Pocket Idea
4. Closure (1 min)
Today we learned about combustion reactions and we need for an organic combustion reaction to
occur inside a car engine. Tomorrow we will learn about substitution reactions.
Assessment/s used in this lesson.
Pre-assessment
Formative
Formative
Summative
Balancing Equations
Discussion/questions
Combustion reaction equations
Engine reaction/short answer activity
Resources: Textbook, https://www.youtube.com/watch?v=bLXDPs7UrXs.