GED® Science: Chemical Reactions & Conservation of Mass (Deep Dive)

Chemical Reactions & Conservation of Mass — Deep Dive Syllabus

Course Overview

This is a focused, self-study deep dive into chemical change. It takes the single
"Chemical Reactions & Conservation of Mass" lesson from the GED® Physical Science
course and opens it out into 24 full sessions.

You do not need any earlier chemistry. Everything is built from the ground up in
plain language, with a labeled diagram in every session. If you can count, you can
do this course — because almost every question in chemistry comes back to counting
atoms and asking where they went.

The one idea underneath all 24 sessions is simple: in a chemical reaction, atoms
are rearranged, never created or destroyed. Conservation of mass, balancing
equations, reaction types, energy changes, and reaction rates are all consequences
of that single sentence.

Course Information

• Program: GED®
• Subject: Science (Physical Science strand)
• Total sessions: 24, grouped into 5 units
• Per session: plain-language teaching + 1 labeled diagram + a worked example + a common-misconception warning + a quick tip
• Diagrams: 24 (one purpose-built for every session)
• Practice questions: 102 lesson MCQs, each with a full explanation
• Difficulty mix: roughly 25% easy, 50% medium, 25% hard
• Extended prompts: 4, provided as study material only
• Prerequisite: none. Helpful but not required: the Atoms & Periodic Table deep dive.

Where This Fits on the GED® Science Test

• GED® Science is about 90 minutes and roughly 34 questions, scored 100–200, with 145 = pass.
• Content weight is Life ~40%, Physical ~40%, Earth & Space ~20%. This course sits inside that Physical Science 40%.
• Chemical reactions and conservation of mass are among the most reliably tested Physical Science topics, and they carry the two skills the whole test rewards: reading a diagram and reasoning from data.
• The test is an evidence test. Most items hand you an equation, a table, or a graph and ask what it actually shows. Sessions 9 and 23 train exactly that.

The Method You Will Use on Every Question

COUNT the atoms → CLASSIFY what is happening → CHECK against conservation.

1. COUNT. Read the formula properly. Coefficients multiply everything; subscripts count only what they touch.
2. CLASSIFY. Is this physical or chemical? Which reaction type? Exothermic or endothermic?
3. CHECK. Does mass balance? Do the atom counts match on both sides? Does the data actually support the answer you picked?

Practice it on all 102 questions until it is automatic.

Course Outline

Required Materials

• This course and its lesson practice questions.
• A notebook (paper or digital) for an error log and for writing out atom counts.
• A periodic table (any printable one will do).
• A basic calculator for the mass-calculation sessions.
• Optional after Unit C: an official GED® Ready Science practice test.

How to Study Each Session

1. Read the session once, slowly, without taking notes.
2. Study the diagram and say its main idea out loud in your own words.
3. Work the example without skipping steps — actually write the atom counts down.
4. Read the ⚠️ misconception warning twice. Those are the exact traps the test uses.
5. Answer the session's MCQs from memory, with no notes.
6. For every miss, write one label in your error log: counting, balancing, classifying, energy, or misread the data.
7. Re-answer missed questions 24–48 hours later. Spaced retrieval is what moves a score.

Completion Standard

You have finished the course when you can take any unfamiliar equation, count its
atoms, name its reaction type, say whether it releases or absorbs energy, and
explain what would speed it up — without looking anything up.

A Word From Your Teacher

Chemistry has a reputation for being the hard one. It is not. It is the tidy one.
Nothing appears from nowhere and nothing vanishes — every single atom is accounted
for, every time. Once that clicks, most exam questions turn into counting problems.
When a question stumps you, go back to counting atoms.

Chemical Reactions & Conservation of Mass — Learning Outcomes

By the end of these 24 sessions, a learner who started with no chemistry background
will be able to:

Chemical change and notation (Sessions 1–4)

• Identify a chemical reaction from its signs: gas, colour change, temperature change, light, or a precipitate.
• Distinguish a physical change from a chemical change by asking whether a new substance was formed.
• Read a chemical formula correctly, applying coefficients, subscripts, and bracket subscripts in the right order.
• Count the atoms of each element in any formula, including bracketed groups such as \(Ca(NO_3)_2\).
• Read a chemical equation as a sentence, and interpret the state symbols (s), (l), (g), and (aq).

Conservation of mass and balancing (Sessions 5–9)

• State the law of conservation of mass and explain it in terms of atoms being rearranged.
• Explain why mass appears to change in an open container but not in a sealed one, in both directions — burning and rusting.
• Balance a chemical equation by adjusting coefficients, never subscripts.
• Balance longer equations in the right order: carbon, then hydrogen, then oxygen last.
• Calculate an unknown reactant or product mass from the masses given.

Types of reactions (Sessions 10–14)

• Recognise synthesis and decomposition from the number of substances on each side.
• Distinguish single from double replacement by counting what swapped places.
• Predict the products of the complete combustion of a hydrocarbon, and explain what incomplete combustion produces and why it is dangerous.
• Identify a precipitation reaction from its state symbols and explain why the solid forms.
• Classify any unfamiliar reaction from its equation using a repeatable method.

Acids, bases, and energy (Sessions 15–19)

• Define acids and bases by the ions they release, and predict the products of a neutralization.
• Read the pH scale, and explain what a change of one or two units means on a logarithmic scale.
• Distinguish exothermic from endothermic reactions, from either a description or a temperature reading.
• Read an energy diagram: identify the activation energy, and tell exothermic from endothermic by where the products sit.
• Explain that breaking bonds absorbs energy and forming bonds releases it, and use the balance between them to predict the overall energy change.

Reaction rates and reading data (Sessions 20–23)

• Use collision theory to explain why particles must meet with enough energy and the right orientation.
• Explain how temperature, concentration, surface area, and catalysts change a reaction rate, and why each one works.
• Explain how a catalyst lowers activation energy without being consumed, and identify enzymes as biological catalysts.
• Interpret a product-vs-time graph: read slope as rate, recognise a flat line as a finished reaction, and compare final yields.

Test behaviour

• Apply COUNT → CLASSIFY → CHECK to any reaction question.
• Avoid the five most common traps in this topic: believing burning destroys matter, changing subscripts to balance, swapping exothermic and endothermic, saying breaking bonds releases energy, and treating a catalyst as used up.
• Answer only from what an equation, table, or graph actually shows, without overclaiming.