definitions

Question 1

what is entropy?

Answer 1

• a measure of the dispersal of energy in a system

Question 2

definition of relative atomic mass

Answer 2

weighted mean mass of an atom relative to 1/12th of the mass of a carbon 12 atom.

Question 3

definition of relative isotopic mass

Answer 3

mass of an atom relative to 1/12th of the mass of a carbon 12 atom.

Question 4

definition of relative molecular mass

Answer 4

mass of a molecule relative to 1/12th of the mass of an atom of carbon-12

Question 5

definition of relative formula mass

Answer 5

compares the mass of a formula unit with 1/12th of the mass of an atom of carbon-12

Question 6

Electronegativity definition

Answer 6

The ability of an atom to attract the bonding electrons in a covalent bond towards itself

Question 7

what is lattice enthalpy of dissociation?

Answer 7

• enthalpy change when one mole of a solid ionic compound is completely dissociated into its constituent gaseous ions under standard conditions
• endothermic

Question 8

What is atomisation energy

Answer 8

The energy required for the formation of one mole of gaseous atoms from an element under standard conditions

Question 9

what is the enthalpy of electron affinity?

Answer 9

The energy required for the formation of one mole of gaseous atoms from an element under standard conditions

Question 10

What is covalent character?

Answer 10

• occurs in ions when two bonded ions have varying size of charges, causing an uneven distribution of charge. Polarisation of anions by cations creates covalent character.

Question 11

what is the enthalpy of solution?

Answer 11

enthalpy change when one mole of ionic solid is dissolved in water to infinite dilution so that the ions no longer interact under standard conditions.

Question 12

what is the enthalpy of hydration?

Answer 12

enthalpy change when one mole of gaseous ions is dissolved in water to form one mole of aqueous ions under standard conditions.