Flashcards in Paper 5 Deck (70):
Rate of reaction
The change in conc of a reactant or product per unit time
Can on,y be determined practically by experiment
The time taken for the concentration of a reactant to reduce by half
The rate right at the start of a reaction (t=0)
Rate determining step
The slowest step in the mechanism of a multi-step reaction
Used up in one step of the reaction and formed in a subsequent step. Not seen as a product or reactant in the overall equation.
Ionic product of water (Kw)
Kc = [H+][OH-]/[H2O]
Eq to left so v small
Kc x [H2O] = Kw = [H+][OH-]
A solution able to oppose changes in pH when small quantities of acid or base are added
(Weak acid and conjugate base)
Enthalpy of neutralisation
The enthalpy change when an aqueous acid reacts with an aqueous base to form 1 mole of water under standard conditions (100kPa, 298K)
The point in a titration at which the volume of one solution has reacted exactly with the volume of the second solution matching the stoichiometric of the reaction
States that if a reaction can take place by more that one route and the initial and final conditions and the same, the total enthalpy change is the same for each route.
Lattice enthalpy (LE)
The enthalpy change when 1 mole of a solid ionic compound is formed from its gaseous ions under standard conditions (298K, 100kPa).
e.g. K+(g) + Cl-(g) ➡️ KCl(s)
Standard enthalpy change of formation (
The enthalpy change when 1 mole of a compound is formed from its constituent elements in their standard States under standard conditions (298K, 100kPa)
e.g. K(s) + 1/2Cl2(g) ➡️ KCl(s)
Standard enthalpy change of atomisation (
The enthalpy change when 1 mole of gaseous atoms forms from the elements in their standard states under standard conditions (298K, 100kPa)
e.g. 1/2Cl2(g) ➡️ Cl(g)
First ionisation energy (
The enthalpy change when 1 electron is removed from each atoms in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions.
e.g. Cl(g) ➡️ Cl+(g) + e-
Second ionisation energy (
The enthalpy change when 1 electron is removed from each ion in 1 mole of 1+ gaseous ions to form 1 mole of gaseous 2+ ions.
e.g. Ca+(g) ➡️ Ca2+(g) + e-
First electron affinity (
The enthalpy change when 1 electron is added to each atom in 1 mo,e of gaseous atoms forming 1 mole of gaseous 1- ions.
e.g. Cl(g) + e- ➡️ Cl-(g)
Second electron affinity (
The enthalpy change when 1 electron is added to each ion in 1 mole of gaseous 1- ions forming 1 mole of gaseous 2- ions.
e.g. O-(g) + e- ➡️ O2-(g)
Used to calculate enthalpy change that cannot be measured direct,y.
Standard enthalpy change of solution (
The enthalpy change when 1 mole of a compound is fully dissolved in water under standard conditions (298K, 100kPa)
e.g. KCl(s) ➡️ K+(aq) + Cl-(aq)
Standard enthalpy change of hydration (
The enthalpy change when 1 mole of aqueous ions are formed from gaseous ions under standard conditions (298K, 100kPa).
e.g. K+(g) + aq ➡️ K+(aq)
Standard entropy change of a reaction (
The entropy change of a reaction in the molar quantities expressed in th equation under standard conditions (298K, 100kPa) in standard States.
Standard entropy of a substance (S⚪️)
The entropy content of 1 mole of a substance under standard conditions (298K, 100kPa).
sum of products - sum of reactants
The overall energy or Gibb's free energy of a system (G)
Results from the contributions of both enthalpy and entropy
The gain of oxygen or hydrogen, the loss of electrons or the increase in oxidation number.
The loss of oxygen or hydrogen, the gain of electrons or the decrease in oxidation number.
Oxidation number of elements
Oxidation number of combined group 1 atoms
Oxidation number of combined group 2 atoms
Oxidation number of aluminum
Oxidation number of hydrogen
Oxidation number of flourine
Oxidation number of oxygen
Oxidation number of chlorine, bromine and iodine
Order of priority of oxidation numbers
Group 1 +1
Group 2 +2
Cl, Br, I -1
Standard electrode potential of a half cell (E⚪️)
The electromotive force (e.m.f.) of a half cell compared with a standard hydrogen half cell, measured at 298K with solution concentrations of 1 moldm-3 and a gas pressure of 100kPa (1 atmosphere).
A d-block element that forms at least one ion with an incomplete d sub-shell.
2 solutions mixed together to produce an insoluble product
Copper (II) hydroxide precipitation reaction
Cu2+(aq) + 2OH-(aq) ➡️ Cu(OH)2(s)
Cu2+ pale blue ➡️ pale blue precipitate (beige in air)
Cobalt (II) hydroxide precipitation reaction
Co2+(aq) + 2OH-(aq) ➡️ Co(OH)2(s)
Co2+ pink ➡️ blue precipitate
Iron (II) hydroxide precipitation reaction
Fe2+(aq) + 2OH-(aq) ➡️ Fe(OH)2(s)
Fe2+ pale green ➡️ green precipitate (rusty-brown in air)
Iron (III) hydroxide precipitation reaction
Fe3+(aq) + 3OH-(aq) ➡️ Fe(OH)3
Fe3+ pale yellow ➡️ rusty-brown precipitate
A central transition metal ion bonded to one or more Luganda by coordinate bonds (dative covalent bonds).
An ion, molecule or atom with a lone pair of electrons that can be donated to a transition metal to form a coordinate bond.
The total number of coordinate bonds between a central metal ion and its ligands.
A ligand that donates one pair of electrons to the central metal ion
A bidentate ligand
Donates two lone pairs of electrons to the central transition metal ion, forming two co-ordinate bonds.
Shape of 6 co-ordinate bonds?
4 co-ordinate bonds shape?
Tetrahedral - 109.5 degrees
For nickel, palladium or platinum - 90 degrees
A reaction in which one ligand in a complex ion is replaced by another ligand.
Cis - 90 degrees
Trans - 180 degrees
Non-superimposable mirror images that rotate plane polarised by equal amounts in opposite directions.
Have no plane of symmetry.
An anti-can we drug that binds to cancer cells' DNA and prevents division as it alters the structure.
The equilibrium constant for the formation of the complex ion from its constituent ions
Large = equilibrium to right = more stable
Hydrogen fuel cell equations
H2 ➡️ 2H+ + 2e-
1/2O2 + 2H+ + 2e- ➡️ H2O
2H2 + O2 ➡️ 2H2O