Reaction Review Slides Reaction Mastery
Chemistry Unit I.8A & I.8B
Signs of a Reaction
How do we know a chemical reaction happened? Just remember G.E.M.S.
G Gas (bubbles or smoke)
E Energy Change (temp/light)
M Mass stays constant
S Solid forms (precipitate)
Law of Conservation of Mass
"Mass is neither created nor destroyed in a chemical reaction."
Reactants
200g
Starting Mass
=
Products
200g
Final Mass
The Balancing Act
Total atom counts must be IDENTICAL on both sides of the arrow.
N2 + 3H2 → 2NH3
2 Nitrogen
2 Nitrogen
Rule #1
Only change the COEFFICIENTS .
Never touch the subscripts! (The tiny numbers belong to the molecule's identity).
Gallery of Reactions
Combustion
Rapidly burning in oxygen . Think fire!
Neutralization
Acid + Base reacts to make Salt + Water.
Oxidation
Slow reaction with oxygen (like rust).
The Energy Flow
Exothermic
Releases heat into the air. The container feels HOT.
Example: A campfire burning.
Endothermic
Absorbs heat from outside. The container feels COLD.
Example: Baking a cake.
Reaction Lab Notes Worksheet Reaction Lab Notes
IPC Standards I.8A & I.8B • Chemical Changes
Student:
Date:
Part 1: The "G.E.M.S." Evidence
G
(Evidence #1)
E
(Evidence #2)
M
(Evidence #3)
S
(Evidence #4)
Non-Evidence Warning
List two physical changes often confused with reactions:
Part 2: Conservation of Mass
200 g HgO → 185 g Hg + ? g O2
Solve for Oxygen:
Scientist to Know:
Antoine Lavoisier
Proved that matter is never created or destroyed, only rearranged.
Part 3: Anatomy of an Equation
Ca + 2H2O → Ca(OH)2 + H2
Left Side
Reactants
Starting substances
Right Side
Products
Newly formed substances
← Task: Circle the Products in the equation above →
Part 4: The Balancing Act
Balance the equation below using coefficients. You must have the same number of atoms on both sides!
N2 +
H2 →
NH3
Balancing Commandments:
Only change the Coefficients (the big numbers).
Never change the Subscripts (the small numbers).
Part 5: Reaction Gallery
Reaction Type What happens? Example Combustion Rapid burning in Oxygen . Burning logs Oxidation Reacting slowly with Oxygen . Iron Rusting Neutralization Acid + Base → Salt + Water Antacid tablet
Part 6: Energy Transfer
Exothermic
Releases energy into the environment. The beaker feels...
Example: Combustion of methane
Endothermic
Absorbs energy from the environment. The beaker feels...
Example: Baking a cake
Self-Assessment Complete?
CHEM-IPC-001
Reaction Balancing Practice Balancing Act
Skills Workshop • IPC I.8B
NAME: ____________________________
The Goal
Total number of atoms on the Reactant side must equal the total number of atoms on the Product side.
ONLY CHANGE COEFFICIENTS!
Pro-Tip: Use the T-Chart
R
P
Count atoms for each element here!
1
H2 +
O2 →
H2O
Scratchpad Area / T-Chart
2
Mg +
O2 →
MgO
Scratchpad Area / T-Chart
3
Li +
F2 →
LiF
Scratchpad Area / T-Chart
4
N2 +
H2 →
NH3
Scratchpad Area / T-Chart
Level Up: Challenge Set
5
CH4 +
O2 →
CO2 +
H2O
6
Al +
O2 →
Al2O3
7
P4 +
O2 →
P2O5
8
Na +
H2O →
NaOH +
H2
!
Conservation Check
Do you have the same number of atoms for every element on both sides? If yes, you're balanced!
Reaction Knowledge Check Quiz Reaction Knowledge Check
IPC I.8A & I.8B • Summative Assessment
NAME: ____________________________
Section I: Fundamentals
1. According to the Law of Conservation of Mass, what happens to atoms during a chemical reaction?
A Atoms are destroyed to release energy.
B Atoms are rearranged into new substances.
C New atoms are created from heat.
D Atoms change their identity to different elements.
2. If 150 g of reactants react completely in a closed system, what will the mass of the products be?
A 75 g
B 150 g
C 300 g
D 100 g
3. Which of the following is the best evidence that a chemical reaction has occurred in a car engine?
A The car changes shape over time.
B Gasoline evaporates into a vapor.
C The engine gets hot and produces exhaust gas.
D The wheels rotate.
4. What are the starting substances in a chemical reaction called?
A Products
B Variables
C Precipitates
D Reactants
5. A reaction that absorbs energy, making the environment feel cold, is:
A Exothermic
B Endothermic
C Oxidation
D Physical
6. In the equation N2 + 3H2 → 2NH3, the coefficient of NH3 is:
A 1
B 2
C 3
D 6
7. Rust forming on an iron nail is an example of which type of reaction?
A Combustion
B Oxidation
C Neutralization
D Endothermic
8. A solid that forms when two liquids are mixed is called a:
A Reactant
B Solution
C Precipitate
D Gas
9. Which of the following is a PHYSICAL change, not a chemical reaction?
A Baking a cake in an oven.
B Dissolving salt in a glass of water.
C Burning a piece of paper.
D Iron reacting with oxygen to form rust.
10. In the equation 2H2 + O2 → 2H2O, the products are:
A 2H2 and O2
B 2H2O
C H and O only
D Heat and Water
11. A student observes bubbles forming when baking soda and vinegar are mixed. This evidence shows:
A A physical change of state.
B The formation of a gas during a reaction.
C That mass has been destroyed.
Reaction Vocab Flashcards Card Front
Reactant
Chemistry Unit
Card Front
Product
Chemistry Unit
Card Front
Exothermic
Chemistry Unit
Card Front
Endothermic
Chemistry Unit
Card Back
A substance that takes part in and undergoes change during a reaction.
Analogy: The Ingredients
Card Back
A substance that is formed as a result of a chemical reaction.
Analogy: The Finished Meal
Card Back
A chemical reaction that releases energy as heat or light.
Environment gets HOT
Card Back
A chemical reaction that absorbs energy from its surroundings.
Environment gets COLD
Card Front
Precipitate
Chemistry Unit
Card Front
3
Coefficient
Chemistry Unit
Card Front
Oxidation
Chemistry Unit
Card Front
Law of Conservation of Mass
Chemistry Unit
Card Back
An insoluble solid that emerges from a liquid solution.
Evidence of a Chemical Reaction
Card Back
The big number in front of a formula that tells you how many molecules you have.
Change these to balance!
Card Back
A chemical reaction in which a substance combines with oxygen .
Example: Iron Rusting
Card Back
States that mass is neither created nor destroyed. The mass of reactants must equal the mass of products .
Antoine Lavoisier
Reaction Teacher Guide Answer Key Reaction Mastery
Teacher Guide & Answer Key
OFFICIAL ANSWER KEY
Quiz Answers (20 Qs)
1. B
11. B
2. B
12. A
3. C
13. B (70g - 5g = 65g)
4. D
14. B
5. B
15. C
6. B
16. B
7. B
17. C
8. C
18. C
9. B
19. B
10. B
20. B
Worksheet Keys
Conservation Prob: 15 g Oxygen (200 - 185 = 15)
G.E.M.S: Gas, Energy change, Mass constant, Solid (Precipitate)
Energy: Exothermic (HOT), Endothermic (COLD)
Balancing Equations Key
1. 2 H2 + O2 → 2 H2O
2. 2 Mg + O2 → 2 MgO
3. 2 Li + F2 → 2 LiF
4. 1 N2 + 3 H2 → 2 NH3
Challenge Set:
5. CH4 + 2 O2 → CO2 + 2 H2O
6. 4 Al + 3 O2 → 2 Al2O3
7. 1 P4 + 5 O2 → 2 P2O5
8. 2 Na + 2 H2O → 2 NaOH + H2
Pacing Guide
Day 1: Slides + Guided Notes (Part 1-3).Tip: Remind students that coefficients multiply subscripts (e.g., 2H2O is 4 Hydrogen atoms).
