Equilibrium Flashcards
Henry’s law
Mass of a gas dissolved in a given mass of solvent at any temp is prop to pressure of gas above solvent
Character of equilibrium
- Possible on in closed system
- Both the opposing processes occur at same rate
- All measurable qualities remain const
Eq. mixture
Mixture of reactants & products in eq state
Eq equation also known as
Law of mass action
Law of chemical eq
At a temp, product of conc of products raised to their stoichio coeff divided by product of conc of reactants raise to their stoichio coeff is a const
Homogeneous system
Reactants & products are in same phase
Delta n =
No of moles of (products -reactants)
Features of eq const
- Applicable only when conc of reactants & products have constant value at eq
- Independent of initial conc
- Temp dependant
- Eq const for Reverse reaction = eq const for forward reaction
Applications of eq const
- Predict extrnt of reaction based on its magnitude
- Predict direction of reaction
- Calc eq conc
If K(c) > 10³
P > R
If K(c) < 10^-3
R > P
If Q(c) > K(c)
Dir of R
If Q(c) < K(c)
Dir of P
If delta G is -ve
Fd dir
Le chatelier’s principle
Change in any factor that determine eq of a system will cause the system to change to reduce & counteract the change
Effect of pressure change on eq
A pressure change obtained by changing volume can affect yield of products where total no of moles of reactants & products are diff
If volume is halved, partial pressure & conc
Doubles
Effect of inert gas
Addition of it at const volume doesn’t change Laotian pressure or conc
Eq const for exothermic when temp increases
Decreases(-ve delta H)
Effect if catalyst
No effect
Ionic eq
Eq btw ions & unionized molecules
Dissociation
Separation of ions in water already existing in solid state of solute
Arrhenius concept of acids & bases
Acids dissociate in water to give H+ & bases OH‐
Conjugate acid-base pair
Acid-base pair that differs only by 1 proton
Bronsted Lowry theory
Acids are capable of donating H+ & bases accepting H+
Bronsted acid is strong when
It’s conjugate base is weak
Lewis acids & bases
Acids accepts e’ pair & bases donates e’ pair
Stronger acid ___ to stronger base
Donates a proton
K(w)
Ionic product of water
K(w) = [H+][OH-] = 10^-14M²
K(w) is ___ dependant
Temp
pH of a solution
-log[H+]
Dissociation/ionization const
K(a)
__ the value of K(a) stronger the acid
Larger
Base ionization const
Eq const for base ionization
K(b) =
c@²/(1-@)
K(net) =
K1 × K2 ×…
__ × __ = K(w)
K(a) × K(b)
Polyprotic acids
Acids that have > 1 ionizable proton per molecule
Extent of dissociation of acid depends on
Strenth & polarity of H-A bond
When strength of H-A bond ___, energy to break it ___ so HA becomes stronger acid
Decreases; decreases
Acid strength in increasing order
HF«HCL«HBr«HI
E’ -vity of A in increasing order
CH4<NH3<H20<HF
Common ion effect
Shift in eq on adding a sub that provides more of an ionic species already present in dissociation eq
Buffer solution
Solutions which resist change in pH on addition of small amounts
Henderson-Hasselbalch equation for acid
pH = pKa + log[Conj base,A-]/[Acid,HA]
Henderson-Hasselbalch equation for base
pOH = pKb + log[Conj acid,BH+]/[base,B]
pH = pKa +
log[Salt]/[Acid]
Henderson equation for acid & base together
pH = pKa + log[Conj acid, BH+]/[Base,B]
Solvation enthalpy is always
-ve
