Table of contents

1. Intro to General Chemistry3h 48m
2. Atoms & Elements4h 16m
3. Chemical Reactions4h 10m
4. BONUS: Lab Techniques and Procedures1h 36m
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

3. Chemical Reactions

Mass Percent

General Chemistry

3. Chemical Reactions

Mass Percent

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Multiple Choice

A 70.0-g iron nail combines with 30.0 g of oxygen to form rust. What is the total mass of the iron nail plus the rust that forms?

40.0 g

100.0 g

230.0 g

It depends on the type of rust that is formed.

There is not enough information to determine the total mass.

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Verified step by step guidance

Identify the law of conservation of mass, which states that mass is neither created nor destroyed in a chemical reaction. Therefore, the total mass of the reactants must equal the total mass of the products.

Determine the mass of the reactants. In this case, the reactants are the iron nail and the oxygen. The mass of the iron nail is 70.0 g, and the mass of the oxygen is 30.0 g.

Calculate the total mass of the reactants by adding the mass of the iron nail and the mass of the oxygen: 70.0 g + 30.0 g.

Understand that the rust formed is the product of the reaction between the iron nail and the oxygen. According to the law of conservation of mass, the total mass of the rust and any remaining iron nail should equal the total mass of the reactants.

Conclude that the total mass of the iron nail plus the rust that forms is the sum of the masses of the iron and oxygen, which is the total mass of the reactants.