Thermodynamics, Entropy, Kinetics

Open systems exchange matter + energy

TRUE — They interact fully with surroundings.

2. Closed systems exchange matter

FALSE — Closed systems exchange only energy.

3. You can exchange matter without exchanging energy

FALSE — Moving matter requires energy.

4. Total energy of universe does not change

TRUE — First Law of Thermodynamics.

5. Work is a state function

FALSE — Work depends on the process/path.

6. Positive work = system does work on surroundings

TRUE — By chemistry sign convention.

7. Heat ≠ temperature

TRUE — Heat is energy transfer; temperature measures average KE.

8. Volume change implies work

TRUE — w = –PΔV.

9. Pressure term in work equation is internal pressure

FALSE — It uses external pressure.

10. Combustion is endothermic

FALSE — Combustion releases heat (exothermic).

11. Freezing is endothermic

FALSE — Freezing releases heat (exothermic).

12. Sweat evaporation is exothermic

FALSE — Evaporation absorbs heat (endothermic).

13. At constant volume, q = ΔH

FALSE — q = ΔU at constant volume; ΔH only equals q at constant pressure.

14. ΔH(fusion) = –ΔH(freezing)

TRUE — Opposite direction processes.

15. Exothermic = weak bonds break, strong bonds form

TRUE — Net release of energy.

16. Large heat capacity = less temperature change

TRUE — More energy required per °C.

17. Heat ∝ temperature change

TRUE — q = mCΔT.

18. ΔHrxn overall = sum of steps

TRUE — Hess’s Law.

19. Spontaneous = no continuous energy input

TRUE — Once started, it continues.

20. Spontaneous = fast

FALSE — Thermodynamics ≠ kinetics.

21. All exothermic reactions spontaneous

FALSE — Some are not (entropy may oppose them).

22. Exothermic reactions do not occur if surroundings are warmer

FALSE — Temperature affects spontaneity but doesn’t forbid reaction.

23. Entropy of universe decreases in spontaneous process

FALSE — It increases.

24. Equal NaCl and KBr mix fully despite diffusion differences

TRUE — Final state still mixed; diffusion rate doesn’t affect final equilibrium.

25. Entropy increases with temperature

TRUE — More microstates accessible.

26. Gases < liquids in entropy

FALSE — Gases have highest entropy.

27. More complex, less symmetric molecules have higher entropy

TRUE — More microstates.

28. Tₛₚₒₙ = ΔH/ΔS

TRUE — The temp at which ΔG = 0.

29. Solutes in dilute solutions do not behave like ideal gases

FALSE — They do behave ideally when dilute.

30. Colligative properties consider solute-solute interactions

FALSE — They depend only on particle count.

31. Osmotic pressure formula is based on ideal gas law

TRUE — πV = nRT.

32. A liquid boils when vapor pressure = internal pressure

FALSE — Boils when vapor pressure = external pressure.

33. Temp ∝ vapor pressure

TRUE — Higher T → more molecules escape.

34. VP depends on external pressure, volume, moles

FALSE — VP is intrinsic; depends only on T and IMFs.

35. Non-volatile solutes contribute to VP

FALSE — Only volatile molecules contribute.

36. Solute increases boiling point

TRUE — Due to reduced vapor pressure.

37. Mixing occurs when solvent–solute IMFs > solute–solute IMFs

TRUE — "Like dissolves like."

38. Gas solubility decreases with pressure

FALSE — Henry's Law

39. Reactions require productive collisions

TRUE — Correct orientation and sufficient energy.

40. Collision theory is not probabilistic

FALSE — It is fully probabilistic.

41. Collision rate depends on concentration, temperature, catalysts

TRUE — All increase collisions or lower activation energy.

42. Reaction rates slow down as reactants decrease

TRUE — Fewer collisions.

43. Stoichiometry determines reaction rate

FALSE — Rate law depends on mechanism, not coefficients.

44. ln[A] vs t linear for zero-order

FALSE — Linear for first-order.

45. Zero-order independent of concentration

TRUE — Rate = k.

46. Sublimation is zero-order

TRUE — Phase changes are often zero-order.

47. Condensation is zero-order

TRUE — Same reasoning.

48. Ignore large-excess reactants in rate law

TRUE — Pseudo-order simplification.

49. In elementary steps, rate-law exponents = stoichiometric coefficients

TRUE — Only true for elementary reactions.

50. Catalysts cannot stabilize transition states

FALSE — That’s exactly what they do.