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1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

11. Nuclear Chemistry

Radioactive Half-Life

GOB Chemistry

11. Nuclear Chemistry

Radioactive Half-Life

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Multiple Choice

What is the concentration of a CO₂ in a container after 4 half-lives if 0.325 mol of CO2 is initially placed into a 5.0 L reaction vessel?

0.020 M

4.06×10^–3 M

8.1×10^–3 M

0.325 M

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Verified step by step guidance

Determine the initial concentration of CO2 by dividing the initial moles of CO2 by the volume of the container: \( \text{Initial concentration} = \frac{0.325 \text{ mol}}{5.0 \text{ L}} \).

Understand that a half-life is the time required for the concentration of a reactant to decrease to half of its initial concentration.

After one half-life, the concentration of CO2 will be half of the initial concentration. After two half-lives, it will be half of that, and so on.

Calculate the concentration of CO2 after each half-life. After 4 half-lives, the concentration will be \( \frac{1}{2^4} \) of the initial concentration.

Multiply the initial concentration by \( \frac{1}{16} \) (since \( 2^4 = 16 \)) to find the concentration of CO2 after 4 half-lives.