UNIT 3 Flashcards
What does it mean if atom economy is 100%?
All of the reactant is converted to product
What is molar volume?
The molar volume of a gas is the volume occupied by 1 mole of a gas at a stated temperature and pressure
What is activation energy?
Activation energy is the minimum kinetic energy required for a reaction to occur
How does a catalyst work in a potential energy diagram?
Catalysts work by providing an alternative pathway for a reaction which is lower in energy
What does a catalyst do to the activation energy?
Catalysts lower the activation energy required for molecules to collide successfully
What are heterogeneous catalysts?
Heterogeneous catalysts are in a different state from the reactants
What are homogeneous catalysts?
Homogeneous catalysts are in the same state as the reactants
Do catalysts have an effect on 🔺H?
No
What is exothermic?
Heat given out to the surroundings
What is endothermic?
Energy absorbed from the surroundings
What is it when energy is required to break bonds?
Endothermic
What is it when energy is released when new bonds are made?
Exothermic
How to work out activation energy?
EA - Reactants
How to work out enthalpy change?
Products - Reactants
How to work out reverse Activation Energy?
EA - Products
How to work out reverse Enthalpy Change?
Reactants - Products
What is enthalpy of combustion?
The enthalpy of combustion is the heat energy given out when 1 mole of fuel burns completely in oxygen
What does the draught shield do?
Keeps heat in
What does Hess’s Law state?
That enthalpy change for a reaction depends only on the initial and final states of the reaction and is independent of the route by which the reaction may occur
What does Le Chatelier’s principle state?
That if a system at equilibrium is subjected to any change, the system will adjust itself to counteract the applied change
What does a catalyst do to equilibrium?
Increases the rate of the forward and the backward reaction allowing equilibrium to be reached faster
Does a catalyst affect the position of equilibrium?
No
What does an increase in concentrations of reactants favour?
The products
What does a decrease in concentrations of reactants favour?
The reactants
What does an increase in concentration of products favour?
The products
What does a decrease in concentrations favour?
The reactants
What does an increase in pressure favour?
The side with the fewest gaseous molecules
What does a decrease in pressure favour?
The side with the most gaseous molecules
What does an increase in temperature favour?
The endothermic reaction
What does a decrease in temperature favour?
The exothermic reaction
What is the forward reaction called in equilibrium?
Endothermic
What is the reverse reaction called in equilibrium?
Exothermic
What will happen when an alkali gets added to equilibrium?
An alkali will remove hydrogen ions from the equilibrium which will move to the right to replace them
What is bond enthalpy?
The energy released when a bond is made in a diatomic molecule
What is mean bond enthalpy?
The average energy released per bond in different environments/compunds
How to work out bond enthalpy?
Bond Breaking - Bond Making
Is bond breaking endothermic or exothermic?
Endothermic
Is bond making endothermic or exothermic?
Exothermic
