definitions Flashcards
zwitterions
a zwitterion is a electrically neutral ion with an equal positive and negative charge
transition elements
a d block element that can form one or more stable ions with a partially filled d subshell
rate of reaction
rate of change in concentration of a reactant or product at a specific point of time
order of reaction
the order of reaction with respect to a given reactant is the power to which the concentration of the reactant is raised in the experimentally determined rate equation
entropy
measure of disorder of a system
3 main basic assumptions of kinetic theory as applied to an ideal gas
- Intermolecular forces of attraction between gas molecules are negligible. 2. The volume of gas molecules is negligible as compared to the volume of the container.
- All molecular collisions are perfectly elastic. There is no loss of kinetic energy during collisions.
strong acid / strong base
weak acid / weak base
strong acid / base : dissociate completely in water to form H3O+ / OH-
weak acid / base : dissociate partially in water to form H3O+ / OH-
Bronsted-Lowry Acid & Base
BLA : proton (H+) donor
BLB : proton (H+) acceptor
Lewis Acid & Base
Lewis Acid : electron pair acceptor
Lewis Base : electron pair donor
standard enthalpy change of hydration
The amount of heat evolved when one mole of free gaseous ions is dissolved in a large amount of water forming a solution at infinite dilution at 298K and 1bar.
Na+(g) -> Na(aq)
standard enthalpy change of solution
the amount of heat absorbed or evolved when one mole of a solute is dissolve in an infinite volume of water under the standard conditions of 298K and 1bar.
NaCl (s) -> Na+ (aq) + Cl- (aq)
lattice energy
the amount of heat evolved when one mole of the solid ionic compound is formed from its constituent free gaseous ions under standard conditions of 298K and 1bar
Le Chatelier’s Principle
If a change occurs in one of the conditions under which a reversible reaction is in dynamic equilibrium, the POE will shift to minimise that change and re-establish equilibrium.
ligands
neutral molecule or anion with at least one lone pair of electrons to form a dative bond with central atom or ion.
standard enthalpy change of reaction
The amount of heat absorbed or evolved when one molar quantities of reactants as shown in the chemical equation react together under standard conditions of 298K and 1bar.
standard enthalpy change of formation
The amount of heat absorbed or evolved when one mol of a substance is formed from its constituent elements, all in their standard states at 298K and 1bar.
Na(s) + Cl(g) -> NaCl (s)
standard enthalpy change of combustion
The amount of heat evolved when one mole of a substance in its standard state is completely burned in excess oxygen under standard conditions of 298K and 1bar.
C3H8 (g) + 5O2 (g) -> 3CO2 (g) + 4H2O (l)
standard enthalpy change of neutralisation
The amount of heat evolved when one mole of water is formed from the neutralisation between an acid and a base, under standard conditions of 298K and 1bar.
standard enthalpy change of atomisation of an element
The amount of heat absorbed when one mole of free gaseous atoms is formed from its element under standard conditions of 298K and 1bar.
1/2 O2(g) -> O(g)
standard enthalpy change of atomisation of a compound
The amount of heat absorbed when one mole of a compound in its standard state is broken into gaseous atoms of its constituent elements under standard conditions of 298K and 1bar.
C3H6(g) -> 3C(g) + 6H(g)
first electron affinity
The amount of heat absorbed or evolved when one mole of electrons is added to one mole of gaseous atoms to form one mole of singly charged gaseous anions.
Cl(g) + e -> Cl-(g)
second electron affinity
The amount of heat absorbed or evolved when one mole of electrons is added to one mole of singly charged gaseous anions to form one mole of doubly charged gaseous anions.
Cl-(g) + e -> Cl2-(g)
bond energy
The average amount of heat absorbed to break one mole of the covalent bond in gaseous state
dynamic equilibrium
A state in a reversible reaction in which the rate of forward reaction equals to the rate of backward reaction and there is no net change in the concentration of the reactants and the products in a closed system
homolytic fission
The breaking of a covalent bond such that each bonding electron goes to each
atom, forming free–radicals.
heterolytic fission
a type of bond breaking process where the splitting of a bond gives rise to an unequal share of bonding electrons to each particle.
buffer
a solution that contains a weak acid or base and its salt
solubility
maximum amount of solute that dissolves in 1dm^3 of water to form a saturated solution at a stated temperature.
solubility product
an equilibrium constant
product of the molar concentrations of constituent ions in a saturated solution, raised to the appropriate powers.
standard electrode potential
Potential difference between a standard hydrogen electrode and the half cell in which the reacting species in the solution are at molar concentrations of 1 moldm^-3 , 298K and gaseous species at pressure of 1bar.
First ionisation energy
The amount of energy needed to remove one mole of electrons from one mole of gaseous atoms to form one mole of singly charged gaseous cations.
Second ionisation energy
The amount of energy needed to remove one mole of electrons from one mole of singly charged gaseous cations to form one mole of doubly charged gaseous cations.
conditions for an ideal gas
high temperature and low pressure
