Reactions require:
1. Reactant molecules to collide
2. Molecules must have sufficient energy
3. Molecules must collide at a favourable orientation
Catalyst decreases Ea of a reaction, not consumed or produced
Factors that affect rate of reaction
1. Concentration
2. Temperature
3. Catalysts
4. Physical nature of reactants
Ideal solution: Δ𝐻𝑠𝑜𝑙𝑛 = 0
Volumes are strictly additive and mixing is complete
Solubility of a gas increases with increased pressure.
Henry’s Law: 𝑃𝐴 = 𝐻𝐴 𝑥𝑎
PA = Partial Pressure of A above solution
HA is Henry’s constant
xA is mole fraction of A in solution
↑ 𝑇 →⁡↓ 𝑆𝑜𝑙𝑢𝑏𝑖𝑙𝑖𝑡𝑦⁡𝑜𝑓⁡𝑔𝑎𝑠
Alternate form of Henry’s Law: 𝐶𝐴 = 𝐻𝐴 𝑃𝐴
CA = Concentration of A in solution
𝑣𝑎𝑝
Raoult’s Law: 𝑃𝐴 = 𝑥𝐴 𝑃𝐴
PA = Partial Pressure of A above solution
PAvap is vapour pressure of pure component
xA is mole fraction of A in solution
The presence of a solute lowers the vapour pressure of
a solvent. Applies to all volatile components of ideal
solutions, as well as non-ideal, dilute solutions
𝐸𝑎
Arrhenius Equation: 𝑘 = 𝐴𝑒 −𝑅𝑇
Ea 1
ln(k) = − ( ) + ln⁡(𝐴)
𝑅 𝑇
𝑘2
𝐸𝑎 1
1
ln ( ) = − ( − )
𝑘1
𝑅 𝑇2 𝑇1
Δ𝑃𝑠𝑜𝑙𝑣𝑒𝑛𝑡 = −𝑥𝑠𝑜𝑙𝑢𝑡𝑒 𝑃𝑠𝑜𝑙𝑣𝑒𝑛𝑡
𝑣𝑎𝑝
𝑀𝑙𝑖𝑞𝑢𝑖𝑑 𝑚𝑠𝑜𝑙𝑖𝑑 𝑃𝑙𝑖𝑞𝑢𝑖𝑑
Msolid = −
(
+ 1)
𝑚𝑙𝑖𝑞𝑢𝑖𝑑
Δ𝑃𝑙𝑖𝑞𝑢𝑖𝑑
Δ𝐻𝑣𝑎𝑝 = 𝐻𝑣𝑎𝑝𝑜𝑢𝑟 − 𝐻𝑙𝑖𝑞𝑢𝑖𝑑 = −Δ𝐻𝑐𝑜𝑛𝑑𝑒𝑛𝑠𝑎𝑡𝑖𝑜𝑛
Δ𝐻𝑓𝑢𝑠𝑖𝑜𝑛 + Δ𝐻𝑣𝑎𝑝 = Δ𝐻𝑠𝑢𝑏𝑙𝑖𝑚𝑎𝑡𝑖𝑜𝑛
Δ𝑇𝑏𝑝 = 𝑖𝐾𝑏 𝑚
Δ𝑇𝑓𝑝 = −𝑖𝐾𝑓 𝑚
m = Molality (mol/kg)
𝑣𝑎𝑝
#⁡𝑜𝑓⁡𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒𝑠⁡𝑖𝑛⁡𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛
Weak IMFs → likely to evaporate → high Pvap (volatile)
Strong IMFs → unlikely to evaporate → low Pvap (non-volatile)
Strength of IMFs directly proportional to boiling point
Normal boiling point: Temperature at which Pvap = 1 atm
𝑃
𝑣𝑎𝑝
Clausius-Clapyron Equation: ln ( 2𝑣𝑎𝑝 ) = −
𝑃1
Δ𝐻𝑣𝑎𝑝
𝑅
1
1
2
1
(𝑇 − 𝑇 )
Assumes a constant Δ𝐻𝑣𝑎𝑝 at all temperatures.
Dew Point Temperature (Tdp): Temperature at which humid
air reaches saturation
%𝑆𝑎𝑡𝑢𝑟𝑎𝑡𝑖𝑜𝑛 =
𝑃𝐴
𝑣𝑎𝑝
𝑃𝐴
(𝑇)
i = van’t Hoff Factor #⁡𝑜𝑓⁡𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑒𝑠⁡𝑑𝑖𝑠𝑠𝑜𝑙𝑣𝑒𝑑
𝐾𝑐 = 𝐾𝑝 (𝑅𝑇)−Δ𝑛 ,⁡and⁡𝐾𝑝 = 𝐾𝑐 (𝑅𝑇)Δ𝑛
𝐿⁡𝑏𝑎𝑟
R⁡=⁡0.08314⁡𝑚𝑜𝑙⁡𝐾
When⁡calculating⁡Kp,⁡pressures⁡must⁡be⁡in⁡unit⁡bar.
When⁡calculating⁡Kc,⁡concentrations⁡must⁡be⁡in⁡unit⁡M
If⁡K⁡>⁡1010,⁡reaction⁡goes⁡to⁡completion
If⁡K⁡<⁡10-10,⁡reaction⁡does⁡not⁡proceed⁡in⁡that⁡direction.
𝐾
Δ𝐻
1
1
2
1
Van’t⁡Hoff⁡Equation:⁡ln (𝐾2 ) = − 𝑅 (𝑇 − 𝑇 )
1
× 100%
𝐼=
𝑄
𝐶𝑜𝑢𝑙𝑜𝑚𝑏
⁡(𝐴𝑚𝑝𝑒𝑟𝑒 =
)
𝑡
𝑠𝑒𝑐𝑜𝑛𝑑
𝑄 = 𝑛𝐹
𝑄 𝐼𝑡
𝑛= =
𝐹 𝐹
𝑐ℎ𝑎𝑟𝑔𝑒⁡𝑢𝑠𝑒𝑑
𝑎𝑐𝑡𝑢𝑎𝑙⁡𝑚𝑎𝑠𝑠
𝜂=
× 100% =
× 100%
𝑐ℎ𝑎𝑟𝑔𝑒⁡𝑠𝑢𝑝𝑝𝑙𝑖𝑒𝑑
𝑡ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙⁡𝑚𝑎𝑠𝑠
𝑅𝑇
𝑜
𝐸𝑐𝑒𝑙𝑙 = 𝐸𝑐𝑒𝑙𝑙
−
ln(𝑄) , 𝑅 = 8.314, 𝐹 = 96485
𝑛𝐹
Concentration cell: galvanic cell with same material at both anode
and cathode. For metals, the half cell with the higher aqueous
concentration acts as the cathode.
At equilibrium: 𝐾 = 𝑒
𝐸𝑜
𝑐𝑒𝑙𝑙 𝑛𝐹
𝑅𝑇
Galvanic cells: generates electricity from spontaneous redox
reactions
Electrolytic cells: Uses electrical energy to drive reactions that
otherwise would not occur spontaneously.
CROA: cathode reduction, anode oxidation
CNAP (in electrolytic cells): cathode negative, anode positive
In galvanic cells, cathode is the positive electrode, anode is the
negative electrode.