1 mole of acid reacts with 1 mole of alkali to form 1 mole of water, under standard conditions of 298K and 1 bar.

1 mole of water is formed in the neutralisation between an acid and an alkali, under standard conditions of 298K and 1 bar.

1 mole of water is formed in the neutralisation between an acid and an alkali, the reaction being carried out in aqueous solution under standard conditions of 298K and 1 bar.

1 mole of acid is neutralised by an alkali to form a salt and water, under standard conditions of 298K and 1 bar.

the enthalpy change when 1 mole of covalent bonds is broken.

the energy required to break 1 mole of a covalent bond between two atoms in the gaseous state.

the energy required to break covalent bonds between atoms in the gaseous state to form 1 mole of gaseous atoms.

the energy released when 1 mole of covalent bond between two atoms in the gaseous state is formed.

always positive (endothermic)

always negative (exothermic)

sometimes positive and sometimes negative

double the value of  $\Delta H\ atomisation$  for gaseous diatomic molecules

equal to the value of  $\Delta H\ atomisation$  for gaseous diatomic molecules

the enthalpy change when 1 mole of the substance is formed from its elements under standard conditions of 298K and 1 bar.

the energy released when 1 mole of the substance is formed from its elements under standard conditions of 298K and 1 bar.

the enthalpy change when 1 mole of elements is used to form a substance under standard conditions of 298K and 1 bar.

the energy released when 1 mole of elements is used to form a substance under standard conditions of 298K and 1 bar.

of a substance is defined as the enthalpy change when 1 mole of the substance is dissolved in a large amount of water under standard conditions of 298 K and 1 bar.

of a substance is defined as the enthalpy change when 1 mole of the substance is fully dissolved in water under standard conditions of 298 K and 1 bar.

of an ion is defined as the enthalpy change when 1 mole of ions is dissolved in a large amount of water such that addition of more water produces no further heat change under standard conditions of 298 K and 1 bar.

of an ion is defined as the enthalpy change when 1 mole of gaseous ions is dissolved in a large amount of water such that addition of more water produces no further heat change under standard conditions of 298 K and 1 bar.

the enthalpy change when 1 mole of a substance is dissolved in a large amount of solvent under standard conditions of 298 K and 1 bar.

the enthalpy change when 1 mole of an ionic compound is fully dissolved in solvent under standard conditions of 298 K and 1 bar.

the enthalpy change when 1 mole of substance is dissolved in a large amount of solvent such that addition of more solvent produces no further heat change under standard conditions of 298 K and 1 bar. (ie. further dilution has no effect)

the enthalpy change when 1 mole of aqueous ions is formed from the dissolution in a large amount of water such that addition of more water produces no further heat change under standard conditions of 298 K and 1 bar.

the energy change when 1 mole of the ionic solid is formed from its separate ions.

the heat energy evolved when 1 mole of the ionic solid is formed from its separate gaseous ions.

the energy required to break 1 mole of ionic bonds to form separate ions.

the heat energy required to break 1 mole of ionic bonds to form separate gaseous ions.

1 mole of atoms is formed in a reaction under standard conditions of 298 K and 1 bar.

1 mole of separate gaseous atoms of the element is formed from the element under standard conditions of 298 K and 1 bar.

1 mole of an element is atomised to form separate gaseous atoms under standard conditions of 298 K and 1 bar.

1 mole of a compound is broken down into its individual atoms under standard conditions of 298 K and 1 bar.

the energy change when 1 mole of electrons is removed from 1 mole of atoms to form 1 mole of gaseous cations.

the energy required to remove 1 mole of electrons from 1 mole of atoms to form 1 mole of gaseous cations.

the energy required to remove 1 mole of electrons from 1 mole of separate gaseous atoms to form 1 mole of gaseous cations.

the energy released when 1 mole of electrons is removed from 1 mole of separate gaseous atoms to form 1 mole of gaseous cations.

the energy change when 2 moles of electrons is removed from 1 mole of atoms to form 1 mole of gaseous X2+ cations.

the energy released when the 2nd mole of electrons is removed from 1 mole of  gaseous atoms to form 1 mole of gaseous X2+ cations.

the energy change when 1 mole of electrons is removed from 1 mole of gaseous X+ cations to form 1 mole of gaseous X2+ cations.

the energy required to remove 1 mole of electrons from 1 mole of gaseous X+ cations to form 1 mole of gaseous X2+ cations.

the energy change when 1 mole of electrons is added to 1 mole of atoms to form 1 mole of anions.

the energy change when 1 mole of electrons is added to 1 mole of gaseous atoms to form 1 mole of gaseous anions.

the energy released when 1 mole of electrons is added to 1 mole of gaseous atoms to form 1 mole of gaseous anions.

the energy required when 1 mole of electrons is added to 1 mole of gaseous atoms to form 1 mole of gaseous anions.

the enthalpy change of a chemical reaction depends only on the initial and final states of the system.

the enthalpy change of a chemical reaction is independent of the reaction pathway taken. 

the enthalpy change of a chemical reaction depends only on the initial and final states of the system, and is independent of the reaction pathway taken. 

the enthalpy change of a chemical reaction via a direct route is equal to the enthalpy change via an indirect route.

sum of clockwise arrows = sum of anticlockwise arrows