OCR A A Level Chemistry Paper 1 Exam with Questions and Answers – 100%
Solved
Bond dissociation enthalpy - ✔✔✔-The enthalpy change required to break a covalent bond with
all species in the gaseous state
Endothermic energy profile diagram - ✔✔✔-products are higher than reactants
Enthalpy change of combustion - ✔✔✔-the enthalpy change when 1 mole of a substance is
burned completely in oxygen under standard conditions
Enthalpy change of formation - ✔✔✔-the enthalpy change when 1 mole of compound is
formed from it's elements in their standard states under standard conditions
Enthalpy change of neutralisation - ✔✔✔-the enthalpy change when an acid and alkali react
under standard conditions to form 1 mole of water
Enthalpy change of reaction - ✔✔✔-the enthalpy change when the reaction occurs in molar
quantities shown in the chemical equation under standard conditions
Exothermic energy profile diagram - ✔✔✔-reactants are higher than products
Heterogenous catalyst - ✔✔✔--catalysts in a different PHASE(state) from the reactants
-therefore the reaction happens over the surface of the heterogenous catalyst
Homogenous Calalyst - ✔✔✔--catalysts in the same phase as the reactants
- usually aqueous
-the reactants combine with the catalyst to make an intermediate species who Ck reacts to form
the products and reform the catalyst
Solved
Bond dissociation enthalpy - ✔✔✔-The enthalpy change required to break a covalent bond with
all species in the gaseous state
Endothermic energy profile diagram - ✔✔✔-products are higher than reactants
Enthalpy change of combustion - ✔✔✔-the enthalpy change when 1 mole of a substance is
burned completely in oxygen under standard conditions
Enthalpy change of formation - ✔✔✔-the enthalpy change when 1 mole of compound is
formed from it's elements in their standard states under standard conditions
Enthalpy change of neutralisation - ✔✔✔-the enthalpy change when an acid and alkali react
under standard conditions to form 1 mole of water
Enthalpy change of reaction - ✔✔✔-the enthalpy change when the reaction occurs in molar
quantities shown in the chemical equation under standard conditions
Exothermic energy profile diagram - ✔✔✔-reactants are higher than products
Heterogenous catalyst - ✔✔✔--catalysts in a different PHASE(state) from the reactants
-therefore the reaction happens over the surface of the heterogenous catalyst
Homogenous Calalyst - ✔✔✔--catalysts in the same phase as the reactants
- usually aqueous
-the reactants combine with the catalyst to make an intermediate species who Ck reacts to form
the products and reform the catalyst
