Module 5 Flashcards
Order w.r.t [A] = 0
Change in [A] = X2
Rate = [X2]^0
So rate stays constant
Order w.r.t [A] = 0
Change in [A] = X3
Rate = [X3]^0 = X1
Rate stays constant
Order w.r.t [A] = 1
Change in [A] = X2
Rate = [X2]^1 = 2
Rate doubles
Order w.r.t [A] = 1
Change in [A] = X3
Rate = [X3]^1 = X3
Rate triples
Order w.r.t [A] = 2
Change in [A] = X2
Rate = [X2]^2 = 4
Rate quadruples
Order w.r.t [A] = 2
Change in [A] = X2
Rate = [X3]^2 = 9
Rate X9
Overall order : 1
Rate equation?
Units of K?
Rate = k [A]
S^-1
Overall order : 2
Rate equation?
Units of K?
rate = k [A]^2
dm^3mol^-1s^-1
Overall order : 3
Rate equation?
Units of K?
rate = k [A]^2 [B]
dm^6mol^-2s^-1
Overall order : 4
Rate equation?
Units of K?
rate = k[A]^2 [B]^2
dm^9mol^-3s^-1
Half-life of reactant, t1/2
Time for the concentration of the reactant to reduce by half
Ea=
A=
R=
activation energy
pre-exponential factor
gas constant (on data sheet)
Enthalpy change of atomization Delta at H theta
The enthalpy change, when one mole of gaseous atoms is formed from its elements under standard conditions
First electron affinity Delta EA1 H theta
The enthalpy change, when one electron is added to each atom in one mole of gaseous atoms to form one mole of gaseous 1- ions
Second electron affinity Delta EA2 H theta
The enthalpy change, when one electron is added to each ion in one mole of gaseous 1- ions, to form one mole of gaseous 2- ions
Entropy, S
The measure of the dispersal of energy in a system. The entropy is greater when the system is more disordered. System becomes energetically more stable when it becomes more disordered.
Standard entropy change of reaction, Delta S theta
The entropy change that accompanies a reaction in the molar quantities to expressed in a chemical equation under standard conditions, all reactants and products being in their standard states
Delta S theta (entropy) = sum of entropy of products - sum of entropy of reactants
(See A2 paper 1 definition list for module 5)
Rate - determining step
The slowest step of reaction mechanism of a multistate reaction
Mole fraction x(A)
Number of moles of A / total number of moles in a gas mixture
Partial pressure p(A)
Mole fraction of A x total pressure P
Bronsted-Lowry acid
A proton (H+) donor
Bronsted-Lowry base
A proton (H+) acceptor
Strong acid
Completely dissociates into its ions in solution to donate a proton
Weak acid
Partially dissociates in its ions in solution to donate a proton
Salt
A compound produced when a H+ ion from an acid is replaced by a metal ion or another positive ion, such as the ammonium ion NH4+
Conjugate acid - base pairs
A pair of two species that transform into each other by the gain or loss of a proton (H+)
pH=
-log[H+]
H+=
10^-pH
pKa=
-log[Ka]
Ka=
10^-pKa
Kw=
[H+][OH-]
Buffer solution
A mixture that minimizes pH change on addition of small amount of acid or base
Lattice enthalpy Delta LE H
Enthalpy change, when one mole of an ionic compound is formed from its gaseous ions
Standard enthalpy change of solution Delta sol H theta
Enthalpy change that takes place with one mole of compound (solute) is completely completely dissolved in water under standard conditions
Standard enthalpy change of hydration Delta hyd H theta
The enthalpy change that takes place when one mole of isolated gaseous ions is dissolved in water filming one mole of aqueous ions under standard conditions
Gibbs Equation
*G = H -TS
*=delta
If G > 0, reaction is not feasible
If G < 0 reaction is feasible
If G = 0 system is in equilibrium
Standard electrode potential, E theta
Of a half cell; is the e.m.f of a half cell compared with a standard hydrogen half cell measured at 298K or -25° C with solution concentrations of 1moldm^-3 and a gas pressure of 100 kPa (1atm)
Species undergoing reduction must have the more positive E theta value
Transition element
A D-Block element that forms an ion with an incomplete d-sub shell
Complex ion
A transition metal ion bonded to one or more ligands by coordinate bonds
Ligand
A molecule ion that can donate a pair of electrons to the transition metal ion to form a coordinate bond
Dative covalent bond (coordinate bond)
Shared pair of electrons, in which one of the bonded atoms provides both electrons for the shared pair
Coordination number
The total number of coordinate bonds formed between central metal ion and its ligands
Monodentate ligand
A molecule or ion that can donate one pair of electrons to the transition metal ion to form one coordinate bond
Bidentate ligand
Donate to lone pairs of electrons to the central metal ion to form two coordinate bonds
Multidentate ligand
Donate more than one lone pair of electrons to the central metal ion to form more than one coordinate bond
Optical isomer
Stereoisomers that are a pair of non-superimposable mirror images of each other
