Table of contents

1. Intro to General Chemistry3h 48m
2. Atoms & Elements4h 16m
3. Chemical Reactions4h 10m
4. BONUS: Lab Techniques and Procedures1h 38m
5. BONUS: Mathematical Operations and Functions48m
6. Chemical Quantities & Aqueous Reactions3h 53m
7. Gases3h 49m
8. Thermochemistry2h 37m
9. Quantum Mechanics2h 58m
10. Periodic Properties of the Elements3h 9m
11. Bonding & Molecular Structure3h 29m
12. Molecular Shapes & Valence Bond Theory1h 57m
13. Liquids, Solids & Intermolecular Forces2h 23m
14. Solutions3h 1m
15. Chemical Kinetics2h 53m
16. Chemical Equilibrium2h 29m
17. Acid and Base Equilibrium5h 1m
18. Aqueous Equilibrium4h 47m
19. Chemical Thermodynamics1h 50m
20. Electrochemistry2h 42m
21. Nuclear Chemistry2h 36m
22. Organic Chemistry5h 7m
23. Chemistry of the Nonmetals2h 39m
24. Transition Metals and Coordination Compounds3h 16m

1. Intro to General Chemistry

Physical & Chemical Changes

General Chemistry

1. Intro to General Chemistry

Physical & Chemical Changes

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Multiple Choice

Which of the following is a physical change?

Milk sours when left out of the refrigerator

Tums (containing CaCO₃) neutralizes stomach acid.

Sugar caramelizing when heated on a skillet.

Tearing a piece of paper.

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Verified step by step guidance

Understand the difference between physical and chemical changes. A physical change involves a change in physical properties without altering the chemical composition, while a chemical change results in the formation of new substances.

Examine the first option: 'Milk sours when left out of the refrigerator.' This involves a chemical change because the milk undergoes fermentation, producing lactic acid and changing its chemical composition.

Consider the second option: 'Tums (containing CaCO3) neutralizes stomach acid.' This is a chemical change as it involves a reaction between calcium carbonate and hydrochloric acid in the stomach, forming new substances like carbon dioxide and water.

Look at the third option: 'Sugar caramelizing when heated on a skillet.' This is a chemical change because heating sugar causes it to break down and form new compounds, changing its chemical structure.

Finally, evaluate the fourth option: 'Tearing a piece of paper.' This is a physical change because tearing paper changes its shape and size but does not alter its chemical composition.