Applications of Hess’s Law (AQA A-Level Chemistry): Flashcards
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Practise the cards
10 cards from this deck
Hess's Law principle
Hess's Law principle
Enthalpy change is independent of route taken
Definition of
Definition of
Enthalpy change when 1 mole of compound forms from elements in their standard states
of element in standard state
of element in standard state
Zero (element formed from itself)
Definition of
Definition of
Enthalpy change when 1 mole burns completely in oxygen
formula using
formula using
products reactants
formula using
formula using
reactants products
Why oxygen ignored in combustion
Why oxygen ignored in combustion
Cannot burn oxygen in oxygen
Main use of Hess's Law
Main use of Hess's Law
Calculate enthalpy changes that can't be measured directly
Example: thermal decomposition
Example: thermal decomposition
Cannot be measured directly; use Hess's Law
Two methods for applying Hess's Law
Two methods for applying Hess's Law
Using enthalpies of formation or combustion