1. Regents Warm-Up Which two characteristics are associated with metals?
(1) low first ionization energy and low electronegativity
(2) low first ionization energy and high electronegativity
(3) high first ionization energy and low electronegativity
(4) high first ionization energy and high electronegativity

2. ENTROPY AIM: What is ENTROPY? DO NOW: What are the oxidation #s in
HOBr
KClO3

3. ENTROPY
ENTROPY (DS): a measure of the randomness or disorder in a system.
A system with more disorder has a greater entropy
What are some examples of entropy?

4. ENTROPY Phase changes are changes in the entropy of the molecules
solidliquidgas
------ENTROPY
Entropy increases as disorder of molecules increases

5. ENTROPY Changes occur so the highest possible entropy is reached.
Increases in entropy favor SPONTANEOUS RXNS
Does dissolving a gas in a liquid (soda) increase or decrease entropy?
This causes a i in entropy
For a reaction, when the amt of gas being produced h the overall entropy will h
Example:
SO3(g)  2SO2(g) + O2(g)
Solutions h in entropy when something is added
h in temp will h entropy

6. ENTROPY Which sample has the greatest entropy? 1. NH3(g) 2. NH3(s)
3. NH3(l)
4. NH3(aq)
Which process is
accompanied by a
decrease in entropy?
1. boiling of water
2. subliming of iodine
3. condensing of water vapor
4. melting of ice

7. ENTROPY Entropy h when: a solid becomes a gas a solid becomes a liquid
a liquid becomes a gas
Something is broken into smaller pieces
In our bodies the desire to become disordered is counteracted by all the energy and heat we produce
Therefore, changes in entropy(DS) and enthalpy (DH) can tell us if a reaction will be spontaneous

8. ENTROPY
A system tends to change toward lower enthalphy and higher entropy
Spontaneous reactions occur naturally and favor product formation
Some reactions may depend on conditions for example:
C6H12O6(s) CO2(g)+H2O(g)
Some endothermic reactions are spontaneous due to an h in entropy (ex. ice melting)
h in entropy favors spontaneous reactions

9. ENTROPY As carbon dioxide sublimes, its entropy 1. decreases
2. Increases
3. remains the same
Which sample has the lowest entropy?
KNO3(l)
KNO3(s)
H2O(l)
H2O(g)

10. ENTROPY At STP, a sample of which element has the highest entropy?
1. Na(s)
2. Br2(l)
3. Hg(l)
4. F2(g)
Which list of the phases of H2O is arranged in order of increasing entropy?
1. ice, steam, and liquid water
2. steam, liquid water, and ice
3. ice, liquid water, and steam
4. steam, ice, and liquid water