Standard enthalpy changes

What are standard conditions?

• 1 atmosphere, 298K

• 2 atmosphere

• 200K

What is the standard enthalpy change of reaction?

• The enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactants and products being in their standard states

• The enthalpy change that takes place when one mole of a substance reacts completely with oxygen under standard conditions, all reactants and products being in their standard states

• The enthalpy change that takes place when one mole of a compound is formed from the constituent elements in their standard states under standard conditions

Which is the Hess cycle for enthalpy change of formation?

Which is the Hess cycle for enthalpy change of combustion?

What does Hess' law state?

• If a reaction can take place by more than one route and the initial and final condition are the same, the total enthalpy change is the same for each route

• If a reaction takes place by more than one route, the total enthalpy change differs for each route

• A reaction cannot take place by more than one route

What is the standard enthalpy change of combustion?

• The enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactants and products being in their standard states

• The enthalpy change that takes place when 1 mole of a substance reacts completely with oxygen under standard conditions, all reactants and products being in their standard states

• The enthalpy change that takes place when 1 mole of a compound is formed from its constituent elements in their standard states under standard conditions

What is the enthalpy change of formation?

• The enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactants and products being in their standard states

• The enthalpy change that takes place when 1 mole of a substance reacts completely with oxygen under standard conditions, all reactants and products being in their standard states

• The enthalpy change that takes place when 1 mole of a compound is formed from its constituent elements in their standard states under standard conditions