Equilibrium Flashcards
Chemical EQ
All R & P reach constant C in a closed system
Dynamic EQ
Rates F & B are equal (usually)
EQ Position
Relative C of R & P in a sys in a dynamic EQ
K Values change based on
- Temp, closed system
- Stays the same regardless of C
- k = P/R
Heterogeneous EQ
- Sys has more than 1 state
- Pure liquids, & solids C can’t change, therefore not included
Magnitude of K
- K < 1: R over P
- K = 1: P & R are similar
- K > 1: P over R
Le Châtelier Principle
When chem sys at EQ is changed, sys will do the opposite to return to EQ
EQ Shift
C of R & P are restored to EQ
More R added
EQ shifts R, to P
Less R added
EQ shifts L, to R
If endo rxn cooled
Shift L bc R has to decrease
If endo rxn heated
Shift R bc increase of nrg to make more P
If exo rxn cooled
Shift R bc nrg is released to counteract change
If exo rxn heated
Shift L bc nrg will be used as P to R
Partial Pressure
- Pressure a gas in a mixture would exert, even alone
- P inverse to V (if V halved, P double)
Factors that changes EQ Sys w/o EQ position
- Catalysts
- Inert gas: unreactivity helps pressure but not partial pressure
- States: EQ only affected by C in same state
If Q < K
EQ shifts R
If Q = K
Sys at EQ
If Q > K
EQ shifts L
Solubility EQ
Dynamic EQ btwn solute & solvent in a sat sol
Ksp
Value from EQ law in a sat solution based on temp
Molar Solubility
- The amount of mol dissolved in 1 L of sat sol
- Combines to calculate for Ksp
If Q > Ksp
Solubility shifts L, precips happens
If Q < Ksp
Solubility shifts R, no precip
If Q = Ksp
EQ, no precip or C change
Common Ion Effect
Decrease of solubility of ionic compound bc of presence of ion existing in both compounds
Arrhenius Theory of Acids & Bases
Acids will make H, bases makes OH
Bronsted-Lowry Theory
Acids are H donors, bases are H acceptors
CA
Acid formed when base accepts H from acid
CB
Base formed when acid loses H to base
Amphiprotic
Able to donate or accept H
If H2O is stronger base than basic sol
EQ shifts R
If basic sol is stronger than H2O
EQ shifts L
Strong acids make
Very Weak CB
Weak acids make
Weak base
Bases with grp 1 & 2 are
Strong bases
Strong bases make
Very Weak CA
Weak bases make
Weak CA
% Ionization
C of ionized acid/initially C of acid
Salts
Solid, ionic compound at SATP
If cation is from grp 1 or 2
NR
If anion is a CB to a strong acid
NR
Anions make
Basic Sol
Cations make
Acidic Sol
If anion is a CB to a WA
Rxn will make basic sol
If cation is a CA to a WB
Rxn will make acidic sol
If both ions react
Anything can happen, must compare Ka & Kb values
If Ka > Kb
Acidic
If Ka < Kb
Basic
If Ka = Kb
Neutral
Metallic Oxides form
Basic solutions
Non-metallic Oxides form
Acidic Solutions
Buffer
- Aq sol w/ its CAB pair to keep pH constant (WA/B + conjugate ion)
- Stops ions from accumulating, replaces another ion
Acidic Buffers have
WA + CB ion
Basic Buffers have
WB + CA ion
When acid is added to a buffered sol
H reacts w/WB
When base is added to buffered sol
OH reacts w/WA
Buffering Capacity
Buffer’s ability to resist change in pH
Strong Acid + Weak Base
Acidic
Strong Base + Weak Acid
Basic
Strong Acid + Strong Base
Neutral
Very Weak Acids make
Strong CA
Very Weak Bases make
Strong CB