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Question 1

Enthalpy change of formation

Answer 1

The enthalpy change that takes place when one mole of a compound is formed from its elements under standard conditions,with all products and reactants in their standard states.

Question 2

enthalpy change of neutralisation

Answer 2

the enthalpy change when one mole of water is formed from the reaction of an acid and alkali under standard conditions

Question 3

enthalpy change of combustion

Answer 3

The enthalpy change when one mole of a substance is burned completely under plentiful supply of oxygen under standard conditions

Question 4

Electronegativity

Answer 4

a measure of an atom’s ability to attract the shared electron pair in a covalent bond towards itself

Question 5

Relative molecular mass

Answer 5

the average mass of a molecule compared to 1/12 of the mass of a carbon 12 atom