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

3. Chemical Reactions

Mass Percent

General Chemistry

3. Chemical Reactions

Mass Percent

Previous problemNext problem

Struggling with General Chemistry?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

Determine the percent composition of nitrogen and oxygen with nitrogen dioxide, NO₂.

25.0% N and 75.0% O

15.5% N and 84.5% O

30.4% N and 69.6% O

69.6% N and 30.4% O

Previous problemNext problem

Verified step by step guidance

Calculate the molar mass of nitrogen dioxide (NO₂) by adding the atomic masses of nitrogen (N) and oxygen (O). The atomic mass of N is approximately 14.01 g/mol, and the atomic mass of O is approximately 16.00 g/mol. Since there are two oxygen atoms, the molar mass of NO₂ is calculated as: Molar mass of NO₂ = 14.01 g/mol (N) + 2 × 16.00 g/mol (O).

Determine the mass contribution of nitrogen in one mole of NO₂. Since there is one nitrogen atom in NO₂, the mass contribution of nitrogen is simply the atomic mass of nitrogen, which is 14.01 g/mol.

Calculate the percent composition of nitrogen in NO₂ by dividing the mass contribution of nitrogen by the molar mass of NO₂ and multiplying by 100 to convert it to a percentage: Percent composition of N = (Mass of N / Molar mass of NO₂) × 100.

Determine the mass contribution of oxygen in one mole of NO₂. Since there are two oxygen atoms, the mass contribution of oxygen is 2 × 16.00 g/mol.

Calculate the percent composition of oxygen in NO₂ by dividing the mass contribution of oxygen by the molar mass of NO₂ and multiplying by 100 to convert it to a percentage: Percent composition of O = (Mass of O / Molar mass of NO₂) × 100.