BCH 2333: L2 Exam Questions and Correct
Answers
Intermolecular interactions create complexity
Monomer --> Oligomer --> polymer
Interactions driven by changes in both:
1) Energy - LOWER energy state fav
2) Entropy - HIGHER entropy state fav (universe fav disorder)
1st Law of Thermodynamics
- Energy cannot be created or destroyed.
- Energy can be interconverted between different forms
electromagnetic radiation - light
potential energy - chemical bonds
work - mechanical, electrical, tension, etc
heat - thermal transfer of energy
Entropy
- a measure of molecular disorder in a system
• proportional to the number of microstates the
components of a system can access without changing
the system MACROscopically
, Microstates = molec speed, vibrat/rotat states, open protein conform.
Ex Gas molec population - Maxwell-Boltzmann distrib:
↑ temp gas, wider range of v = ↑ # of microstates = ↑ entropy
Entropy (alternate def)
how much and how widely the energy is spread out.
Which system has the most entropy?
1) A warm or cold penny? Warm
2) 1 mol of an ideal gas at 298 K in a 1 L
container or a 10 L container? 10L
- Spread out over ↑ Volume = ↑ entropy
1) 1 mol of gas at 298K, 1 bar, composed of
propane or ethane?
More bonds, ↑ degree of freedom (rot + vib)
2nd Law of Thermodynamics
"The entropy of the universe must increase for any spontaneous process"
(Why it is spontaneous, b/c the universe favours inc entropy!)
Entropy = degrees of freedom = microstates
Universe = system + surroundings
Answers
Intermolecular interactions create complexity
Monomer --> Oligomer --> polymer
Interactions driven by changes in both:
1) Energy - LOWER energy state fav
2) Entropy - HIGHER entropy state fav (universe fav disorder)
1st Law of Thermodynamics
- Energy cannot be created or destroyed.
- Energy can be interconverted between different forms
electromagnetic radiation - light
potential energy - chemical bonds
work - mechanical, electrical, tension, etc
heat - thermal transfer of energy
Entropy
- a measure of molecular disorder in a system
• proportional to the number of microstates the
components of a system can access without changing
the system MACROscopically
, Microstates = molec speed, vibrat/rotat states, open protein conform.
Ex Gas molec population - Maxwell-Boltzmann distrib:
↑ temp gas, wider range of v = ↑ # of microstates = ↑ entropy
Entropy (alternate def)
how much and how widely the energy is spread out.
Which system has the most entropy?
1) A warm or cold penny? Warm
2) 1 mol of an ideal gas at 298 K in a 1 L
container or a 10 L container? 10L
- Spread out over ↑ Volume = ↑ entropy
1) 1 mol of gas at 298K, 1 bar, composed of
propane or ethane?
More bonds, ↑ degree of freedom (rot + vib)
2nd Law of Thermodynamics
"The entropy of the universe must increase for any spontaneous process"
(Why it is spontaneous, b/c the universe favours inc entropy!)
Entropy = degrees of freedom = microstates
Universe = system + surroundings
