1. Lab 8Lab 8
“Endo and Exo
The ReactionTwins”

2. The student will investigate and
understand chemical changes in
matter
The student will be able to recognize
that some types of chemical reactions
require continuous input of energy
(Endothermic) and others release
energy (Exothermic)

3. Endothermic Reaction
Exothermic Reaction

4. A chemical
reaction that
requires
continuous input
of energy.
It feels cold. Endothermic reaction of barium hydroxide
and an ammonium salt. Mix the two
solids; they react, and the products
dissolve in water of hydration. The
reaction flask may be passed around for
students to feel how cold it is.

5. A chemical
reaction that
continuously
releases
energy.
It feels hot.
Light Energy could be released in
the exothermic reaction taking place
in things such as glow sticks.

6. Temperature change is an
indicator or clue of a chemical
reaction
The temperature change happens
because of the combination of
chemicals and energy

7. There are two types of
chemical reactions that cause
a temperature change
Endothermic Reactions
Exothermic Reactions

8. Endothermic and Exothermic
Reactions are shown using a line
graph

9. The graph is written as change in
temperature over time

10. In Endothermic Reactions,
there is a decrease in
temperature or a temperature
drop.

11. Endothermic Reactions require
more energy to break the
original chemical bonds and
form new ones

12. Energy is absorbed from the
environment through a
continuous input of energy and
the product feels cold
Cold Packs

13. Endothermic
in Blue

14. Exothermic Reactions give off
energy in the form of thermal
energy (heat). (increase in
temperature)

15. Exothermic Reactions require
Less energy is to break bonds to
form new ones
Burning wood, paper, hand
warmers

16. We use a line graph to show the
changes in endothermic and
exothermic reactions

17. Exothermic
reaction in
Green

18. The steeper the line(Slope) the
faster the energy change