PRACTICE: Which reaction is most likely to have a positive ∆S of system? a) SiO 2 (s) + 3 C (s) → SiC (s) + 2 CO (g) b) 6 CO 2 (g) + 6 H 2 O (g) → C 6 H 12 O 6 (s) + 6 O 2 (g) c) CO (g) + Cl 2 (g) → COCl 2 (g) d) 3 NO 2 (g) + H 2 O (l) → 2 HNO 3 (l) + NO (g)

Which reaction is most likely to have a positive delta s of system? Alright. So the first one we have are silicon with 2 oxygens in a solid form, then we have it reacting with 3 moles of carbon solid to produce silicon carbide carbonide plus 2 moles of carbon monoxide gas. This one would have a positive delta s because what do we increase? We increase the number of moles of gas. The reactants we had no gases, but now for products we have 2 newly created gas molecules. Increasing the moles of gas always increases the entropy. Let's look at the other options. Here we have in total 12 moles of gas as reactants, but over here we only have 6 moles of gas. So the moles of gas went down which would mean our entropy goes down, so it'd be negative delta s. For the next one, we have 2 reactants combined to give us one product, so we combine, we formed bonds, that's a negative delta s. And then finally we have what? 3 moles of gas as reactants, and now we're only down to 1 mole of gas as product. That's again a decrease in entropy, so negative delta s. So only option a would give us a positive delta s of the system.

PRACTICE: Which reaction is most likely to have a positive ∆S of system? a) SiO 2 (s) + 3 C (s) → SiC (s) + 2 CO (g) b) 6 CO 2 (g) + 6 H 2 O (g) → C 6 H 12 O 6 (s) + 6 O 2 (g) c) CO (g) + Cl 2 (g) → COCl 2 (g) d) 3 NO 2 (g) + H 2 O (l) → 2 HNO 3 (l) + NO (g)

CO (g) + Cl 2 (g) → COCl 2 (g)

3 NO 2 (g) + H 2 O (l) → 2 HNO 3 (l) + NO (g)

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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

7. Energy, Rate and Equilibrium

Entropy (Simplified)

GOB Chemistry

7. Energy, Rate and Equilibrium

Entropy (Simplified)

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Multiple Choice

PRACTICE: Which reaction is most likely to have a positive ∆S of system?
a) SiO₂ (s) + 3 C (s) → SiC (s) + 2 CO (g)
b) 6 CO₂ (g) + 6 H₂O (g) → C₆H₁₂O₆ (s) + 6 O₂ (g)
c) CO (g) + Cl₂ (g) → COCl₂ (g)
d) 3 NO₂ (g) + H₂O (l) → 2 HNO₃ (l) + NO (g)

SiO₂ (s) + 3 C (s) → SiC (s) + 2 CO (g)

6 CO₂ (g) + 6 H₂O (g) → C₆H₁₂O₆ (s) + 6 O₂ (g)

CO (g) + Cl₂ (g) → COCl₂ (g)

3 NO₂ (g) + H₂O (l) → 2 HNO₃ (l) + NO (g)

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Verified step by step guidance

Identify the concept of entropy (∆S) which is a measure of the disorder or randomness in a system. A positive ∆S indicates an increase in disorder.

Examine each reaction to determine the change in the number of gas molecules, as gases contribute more to entropy than solids or liquids.

For reaction (a), SiO2 (s) + 3 C (s) → SiC (s) + 2 CO (g), note that the reaction produces 2 moles of gas from solid reactants, indicating an increase in entropy.

For reaction (b), 6 CO2 (g) + 6 H2O (g) → C6H12O6 (s) + 6 O2 (g), observe that the number of gas molecules decreases, suggesting a decrease in entropy.

Compare all reactions and identify that reaction (a) is most likely to have a positive ∆S because it results in the formation of gas molecules from solid reactants, increasing the system's disorder.